Warmer Summers Impact Local Rhododendrons

From sun scorch to lace bug, local gardeners protect their beloved rhododendrons with these conscientious tips.

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By Sonja Nelson, Skagit County WSU Extension Master Gardener

Rhododendrons in our gardens, along with the native state flower Rhododendron macrophyllum, the Western or Pacific rhododendron in our woodlands, are facing the vagaries of climate change here in the Pacific Northwest as well as worldwide. Gardeners in our moderate climate can no longer assume our benevolent climate will continue its unstinting support for the genus Rhododendron. According to the World Meteorological Organization, the average global temperature in 2024 was the warmest year on record at about 2.7° F or 1.55° C above preindustrial levels. Higher temperatures do not bode well for rhododendrons. They like moderation!

Rhododendrons have a long history in the Pacific Northwest. Native Americans used the flowers of rhododendrons in their dance rituals long before western plant hunter Archibald Menzies identified the R. macrophyllum. Menzies was the surgeon-botanist for Captain George Vancouver on board the British ship ‘Discovery’ in 1792. The R. macrophyllum, or Western rhododendron, was sent to King George III and introduced to the Kew Gardens in London. The discovery brought together the British and American plant people who eventually produced a creative milieus communities of rhododendron enthusiasts that made the rhododendron the “King of Shrubs” on both sides of the Atlantic.

References to the Western rhododendron (Rhododendron macrophyllum) date back to native Americans using rhododendron flowers in their dance rituals long before the late 1700s. © Photo: Sonja Nelson

One hundred years after Menzies documented finding the Western rhododendron, the state of Washington sought a representative flower to display in the 1893 Chicago World Fair exhibit. The Washington State Fair Commission asked the state’s women to decide. A letter-writing campaign began, pitting the native rhododendron against, among others, the clover. (The vote was Western rhododendron 7,704 and clover 5,729.) It was officially designated the Washington State flower in 1959.

However, between the time the Western rhododendron was presented at the Chicago World Fair, rhododendron species from Asia, particularly the Himalayas, had been discovered by dedicated British plant hunters and sent back to Britain to adorn gardens there with their vibrant colors and to hybridize. Many Asian species and hybrids were also brought to America, where nurseries introduced them to the Pacific Northwest. Gardeners welcomed them with enthusiasm and love. And the rhodies loved them back with their stunning performance!

Meanwhile, Washington state’s native Western rhododendron grew in its native woodlands as the quietly attractive relative of the more flamboyant Himalayan species. In the 1970s the Western rhododendrons regained popularity as gardening with native plants became popular with the backing of  WSU Extension and the Washington Native Plant Society. In 1979, the First World Climate Conference declared climate change a global issue, and rhododendron gardeners’ concern turned to the native Western rhododendron and its environment, along with concern for their rhododendron species and hybrids from afar. The natural environment of the Pacific Northwest, so well suited for much of the genus Rhododendron, was becoming jeopardized by temperature increases and other disturbances to its blissful climate.

The Western or Pacific rhododendron is native to the woodlands of the Pacific Northwest. Image © Oregon State University

One of the most sun-hardy of all rhododendrons, the Jean Marie Rhododendron is noted for its large trusses of deep red, trumpet shaped flowers. © WSU Clark County

The complexity of a warming climate makes it difficult to predict precisely how rhododendrons will be impacted by our specific climate and what to do if it does. For instance, if temperatures increased enough to leave visible sun spots on the leaves of rhododendrons, the rhododendrons could simply be moved to a site with partial shade. However, the effect of a warming climate on plants is not always straightforward.

One solution to protect rhododendron gardens from climate change damage is to find varieties-both species and hybrids-that are tolerant of temperature increase and ensuing weather extremes.

A member of the American Rhododendron Society, C.J. Patterson of Massachusetts, has focused his interest in rhododendrons on finding drought-tolerant rhododendrons for East Coast gardens. He writes that “rhododendrons, in general, are mostly very resistant to dry conditions once they are established,” citing R. carolinianum, R. maximum, and R. catawbiense as drought tolerant. He says one of the most drought-tolerant rhododendron hybrids is the hybrid ‘PJM’ (R. minus var. Carolinian Group x R. dauricum) and other hybrids of the same cross.

The director of the German Rhododendron Society, Hartwig Schepker, supports the idea that the genus Rhododendron is diverse enough to cope with the challenges posed by extreme climate conditions, saying we find them or create new hybrids that will be up to the job.

Another rhododendron expert is Glen Jamieson, the editor of the Journal American Rhododendron Society, who often writes about the impact of climate change on rhododendrons, which, he says, has been relatively minor annually. In coming publications, he plans to summarize the weather impacts on his garden in British Columbia over the past 40 years, where there have been extreme cold, heat, precipitation, and wind events-all of which can be attributed to a changing climate.

Since it is difficult, if not impossible, to predict precisely the effects of climate change on rhododendrons in the future, conscientious basic care is the best way to help them survive hard times in the future. Washington State University lists watering, fertilizing, and mulching as basic care.

Basic Care for Rhododendrons
Washington State University Extension recommends this regimen of basic care:

Watering

• Water rhododendrons at least once a week, or when the top inch of soil feels dry.
• Avoid waterlogged soil, which can damage rhododendrons.
• Water well in the fall to prepare for winter

Fertilizing

• Use a fertilizer made for acid-loving plants.
• Fertilize in the spring when buds swell and in the fall after flowering.
• Follow the product label recommendations.

 

Mulching

• Use coarse organic mulch, like wood chips, to cover the root zone.
• Keep mulch at least 4 inches deep, but don’t let it touch the base of the plant.
• Mulch helps conserve water, reduce weeds, and moderate soil temperatures

Other Tips

• Plant rhododendrons in well-drained acidic soil
• Avoid dense or compacted soil
• Provide shade or semi-shade
• Prune out dead flowers
• Avoid overhead watering
• Maintain good air circulation
• Prevent injury to reduce the chance of infection
• Clean up and destroy fallen leaves

A Unique Opportunity to Observe Local Climate Change Impact
The coordinators of the various gardens within the WSU Extension Master Gardener Discovery Garden west of Mount Vernon were questioned about possible damage in their gardens due to recent summers with high temperatures. Five coordinators reported no change, and four coordinators reported slight changes. Ironically, six coordinators reported damage from unusual cold spells. The Rhododendron Garden coordinator, however, reported extensive damage to a large planting of small-leaved rhododendrons due to warming temperatures.

Lace bug symptoms on rhododendron leaves © WSU Hortsense Photo by: C.R. Foss

Photo © Sonja Nelson

Rhododendrons are divided into two natural divisions: the lepidotes and the elepidotes. Small-leaved rhododendrons belong to the lepidote division based on the tiny scales on the undersides of their leaves. Elepidotes do not have scales and tend to be large-leaved.

Sun scorch on the leaves of rhododendrons has long been an occasional problem for gardeners, but the warming caused by climate change has introduced a new, insidious avenue for damage–the rhododendron lace bug (Stephanitis rhododendri). Believed to have migrated from California, lace bugs have taken advantage of the longer growing season in the Pacific Northwest and can complete their life cycle, where, in 2023, in the Rhododendron Garden, it laid eggs and, as a result, destroyed a planting of rhododendrons.

Rhododendron lace bug (Stephanitis rhododendri Horvath) © Insect Images Photographers: Seastone, L. and B. Parks

Azalea lace bug (Stephanitis pyrioides) © Photo: Jim Baker, North Carolina State University, Bugwood.org

The lace bug affected rhododendrons with small leaves, mainly in the island meadow section of the Rhododendron Garden, namely hybrids ‘Ramapo,’ ‘Ginny Gee,’ and ‘Patty Bee.’

The rhododendron lace bug has one generation per year. It overwinters as eggs laid on the underside of leaves. Nymphs are about 1/8 inch long and are spiny. Adults are about 1/8 inch long and whitish tan with lacy-looking wings. Damage is usually apparent by early to mid-July. The lace bug sucks on the undersides of leaves and causes stippling on the upper surface of the leaves and tar-like deposits of excrement on the lower surface. Repeated infestations may result in yellowed, sickly plants. Spraying the undersides of the plants to remove the lace bugs was considered impossible because the leaves grow so densely and so close to the ground; thus the affected plants were removed. New planting will take place in 2025.

The related azalea lace bug (Stephanitis pyrioides) has four to five life cycles annually. It infects rhododendrons also but has not been found in the Rhododendron Garden section of the Discovery Garden. Both types of lace bug overwinter.

The lace bug is not to be confused with lacewing insects (Chrysoperla species) which are native to the Pacific Northwest and important natural predators providing biological control of aphids.

Treatment for Lace Bug
For non-chemical treatment, Washington State University recommends hand removal of adults and nymphs regularly to limit the amount of visible damage. This can be done with a strong spray of water.

If you choose to use a chemical treatment, two recommended pesticides that are legal in Washington are:     

• Safer Brand BioNEEM Multi-Purpose Insecticide and Repellent Concentrate [Organic] Active ingredient: azadirachtin [EPA registration number: 70051-6-42697]
• Safer Brand Garden Defense Multi-Purpose Spray Concentrate [Organic]
  Active ingredient: clarified hydrophobic extract of neem oil [EPA registration number: 70051-2-42697]

The best time to treat is May and June. For more information, download the WSU fact sheet on rhododendrons and lace bugs @ (https://hortsense.cahnrs.wsu.edu/fact-sheet/rhododendron-rhododendron-lace-bug/).

The Rhododendron Garden in the Discovery Garden allows the public to view plants as they grow in our specific climate. The damage to some of the small-leaved rhododendrons is sad to see, but it gives gardeners the knowledge to make necessary changes in their gardens to keep them beautiful.

Soon, spring will once again bring forth the eye-catching, luscious blooms on the rhododendron hybrids planted in our gardens and the quietly elegant blooms of our native Western rhododendron at the edges of our woodlands.

REFERENCES AND RESOURCES:
Dale-Crunk, B. (2024) Personal communication.

NASA https://climate.nasa.gov/vital-signs/global-temperature/?intent=121

Skagit Climate Science. Air Temperature and Precipitation Retieved at: (http://www.skagitclimatescience.org/skagit-impacts/temperature-and-precipitation-and-ecosystems/#nw-is-warmer).

Washington State University. (2024) Rhododendron: Rhododendron and Lace Bug Retrieved at: (https://hortsense.cahnrs.wsu.edu/fact-sheet/rhododendron-rhododendron-lace-bug/).

Pojar, J. and MacKinnon, A. (1994) Plants of the Pacific Northwest, B.C. Ministry of Forests and Lone Pine Publishing

Nelson, S. (Compiler) (2001) The Pacific Coast Rhododendron Story American Rhododendron Society. Binford & Mort Publishing, Portland, Oregon.

University of Washington: Pruning and Caring for Rhododendrons. https://depts.washington.edu/hortlib/pal/pruning-and-caring-for-rhododendrons/

Washington Native Plant Society (2022) Coast Rhododendron: Washington’s State Flower Retrieved at:https://www.wnps.org/blog/coast-rhododendron-washington-state-flower?highlight=WyJyaG9kb2RlbmRyb24iXQ==

World Meteorological Organization (2025) January 2025 sees record global temperatures despite La Niña Retrieved at: https://wmo.int/media/news/january-2025-sees-record-global-temperatures-despite-la-nina

 

ABOUT THE AUTHOR:
Sonja Nelson is a Skagit County WSU Extension Master Gardener, Class of 2009.

Questions about home gardening or becoming a master gardener may be directed to Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Washington State University Extension helps people develop leadership skills and use research-based knowledge to improve economic status and quality of life. Cooperating agencies: Washington State University, US Department of Agriculture, and Skagit County. Extension programs and policies are available to all without discrimination. To request disability accommodations contact us at least ten days in advance.

Is Bamboo for You?

If you love bamboo, be a good neighbor and understand how to select, grow, and maintain the plant.

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By Kay Torrance, Skagit County WSU Extension Master Gardener

Bamboo is alternatingly loved and hated by home gardeners. Typically, gardeners are firmly planted in one camp or the other. Full disclosure: I love bamboo. With its soft green glow and exotic sculpted leaves rustling in the breeze, the impact of bamboo in a garden can be transforming. It invokes tranquility and quiet contemplation. Bamboo is unlike any other plant in the garden.

Bamboo resists drought, deer, pests, and disease.  As a landscape plant, it is self-mulching and evergreen. It grows well in poor soil. With all this going for it, why do so many cringe at the thought of growing bamboo? Bamboo has a reputation for being invasive and difficult to maintain. Is that a tired stereotype? Bamboo is not maintenance-free, few plants in the garden are. It requires at least annual maintenance and more extensive care every 3-4 years. Much less than a fruit tree but more than a cactus.

Often, bamboo is planted as a fast-growing evergreen privacy border, with the expectation that no pruning or maintenance will ever be needed once it is grown. Is that reasonable for any plant? Before planting, was the selected bamboo evaluated to see if it had a clumping or running habit? Whether it was short or timber-sized? The key to being in zen with your bamboo is understanding how to select, grow, and maintain the plant.

Phyllostachys Edulis ‘Moso’ is a common timber variety growing in Arashiyama Bamboo Forest in Kyoto, Japan. Photo © Bobbi Lemme

Phyllostachys nigra ‘Black Bamboo’ showing the smaller canes from the purchased nursery pot in the back and the new larger green culms produced two years later. Photo © Kay Torrance

What is Bamboo?
Bamboo is the tallest member of the grass family. Believed to originate in China, over a thousand species are growing worldwide in various climates. Some timber varieties grow over 100 feet tall with culms over a foot in diameter. In lush tropical environments, varieties can grow three feet a day. You can also find bamboo thriving in the snow-covered foothills of the Himalayas. Most bamboos originate from Asia, but several species of the genus Arundinaria are native to the Southeastern US.

Botanically, the plant is an evergreen perennial. Like all grasses, it has a woody ringed hollow stem known as a culm (commonly called canes). The joints along the culms are called nodes, and branches grow out above the nodes. The plants have an underground stem called a rhizome, and roots are clustered along the rhizome. New plants erupt from rhizomes as buds. These are called shoots once they emerge from the ground. New culms are protected by papery sheaths, which fall off when they mature and harden.

Not only is bamboo beautiful, it is functional. Strong enough for buildings, furniture, and fences, it is still used today in Asia as scaffolding to build skyscrapers. It is a renewable resource for home décor, garden stakes, brooms, livestock food, and charcoal. Tender baby culms are a dietary delicacy.

How Bamboo Grows
Bamboo produces new culms from rhizomes in the spring. They grow rapidly for 30 to 60 days, obtaining their full height. Only then will they start producing limbs and leaves. After the spring surge, bamboo does not generally grow taller or produce new culms until the following year. Individual culms can last 5-15 years before dying if not damaged. Bamboo rarely flowers, and it is typically propagated by division.

Bamboo is generally grouped by rhizome growth habits such as clumping or running. Growth habit is the single most important consideration when choosing a variety for your landscape! Clumping bamboos have U-shaped rhizomes that produce culms that are a shorter distance from the parent. Running bamboos naturally spread by sending new rhizomes many feet away from the parent plant. One hears stories of bamboo taking over yards and damaging sidewalks and foundations. To avoid such problems, carefully choose a variety suited to your selected location. Consider pots or containers instead of direct planting.

Newly divided bamboo typically takes 3-5 years to reestablish its root system and produce full-size canes. More vigorous running varieties take less time, and clumping varieties take longer. In an established grove, the new culms are roughly the same size as the existing ones. Proper sunlight, water, and soil nutrition will establish new plants quickly. Adequate watering in the first year is essential while the roots are established.

The growth habit of above-ground branches also varies between bamboos and is important when selecting bamboo for the right look in your yard. Some bamboos suppress branches on the lower nodes, creating a very upright and open appearance. Some are naturally weeping and have a more informal look. Some have a single branch emerging above a node, while others have multiple branches at each node, producing dense foliage. These branches can be pruned, but selecting a variety with the desired growth characteristics is easier than pruning each year.

Qiongzhuea tumidissinoda ‘Walking Stick’ bamboo has enlarged nodes. It is a fun variety that grows up to 12′ (less in a container). It is also an aggressive running bamboo, sending rhizomes a long distance from the source and likes to jump barriers. Photo © Kay Torrance

Bamboo garden and planter studio. Photo courtesy of Bamboo Garden Nursery

Varieties and Selection
The American Bamboo Society lists almost 500 kinds of bamboo grown in the US and Canada. Sizes vary from under a foot to over 100′ tall. Many bamboos have gold, blue, red, black, and variegated canes. The nodes can be straight or bulbous, like the walking stick bamboo in Bu Belly or Chinese. There are even varieties with zigzag canes. See the section below for a list of varieties suited for the PNW.

The Pacific Northwest is not an ideal growing location for bamboo. Bamboos grow slower in our cool summers with limited rain. Some bamboos that are invasive elsewhere are not a problem here. For example, Phyllostachys aurea, common ‘Golden’ or ‘Fishing pole’ bamboo, has a reputation for being invasive. However, here, bamboo grows slower than in climates where summer temperatures average 90+ degrees Fahrenheit. If you plant it in the shade, the growth will be slower. A neighbor planted Phyllostachys aurea next to a water garden over 50 years ago. Initially, it thrived, but as conifers grew up around the area, it struggled for light and recently died. Like other grasses, most bamboos can take full sun and will thrive in it. Some prefer part shade. None will grow in full shade.

Is bamboo right for you? Before adding bamboo or any plant to your garden, think about your goals and expectations:

• What do you want to accomplish? Privacy? Texture? Most people select bamboo as a natural evergreen privacy screen or a focal point for their garden.
• How much room do you have? Do you want a forest, a clump, or a pot on your deck? There are varieties appropriate for all of these uses.
• How much maintenance do you have time for? Clumping varieties require less root pruning and are less likely to escape.
• How tall should the plants grow? Although bamboo tolerates pruning well, the resulting boxy look might not be desired. Selecting a variety that matures to the desired height without topping is better.
• Do you want small, delicate leaves that tinkle in the wind or large leaves that rustle? I have a patch of Pseudosasa japonica ‘Japanese Arrow’ bamboo. Its large leaves rustle delightfully in a breeze, growing only to 15′. It provides year-round privacy but is a running bamboo, so its growth needs to be limited with semi-annual root pruning.
• Is there a color preference? In addition to solid green, culms can be yellow, orange, red, blue, silver, or even variegated. Leaf colors can be shades of green, yellow, blue, silvery, and variegated. Beware that many colorful bamboos are from the tropics, so choices for the PNW are limited.
• Do you want pencil-width stalks, medium size, or a diameter measured in inches? If you want a cane that is an inch across, make sure you have room for a forest. If you choose a large-diameter bamboo, you can have bamboo canes for projects around your home. Small-diameter culms can provide endless plant stakes, craft supplies, and weaving material. Having uses for pruned canes makes maintenance enjoyable.
• Are you looking for an open upright structure or a dense natural fence? Running bamboos have more space between the culms and a more upright appearance. Clumping bamboo culms grow more closely together. Some bamboos have more horizontal branches that make a good privacy screen.

If you are considering bamboo:

• Avoid buying large (over ½ mature culm size) running bamboo unless you are committed to containing and maintaining it. See maintenance requirements below.
• Avoid planting a hedge of any type of bamboo along a property line for privacy and not building a containment system along the property line to keep it on your side.
• Avoid planting bamboo in areas where there is irrigation or where you fertilize routinely. It will grow fast and require more maintenance. Bamboo planted next to turf lawns will soak in all that water and fertilizer and grow quickly.

Planting and Management
Even though bamboo is likely filling the role of a shrub or tree in your yard, manage it like the grass it is. If you want to contain a plot of grass, you either put a barrier in the ground to redirect the root growth, or you can edge (cut) the roots. The same method is required to contain a stand of bamboo. Bamboo rarely seeds and is surprisingly difficult to propagate from seed. 
Container Planting
The most obvious barrier to preventing bamboo spread is planting it in a pot or container. Like any potted plant, it will need to be thinned every few years or become a root-bound mess. Choose straight-sided pots and use a perennial root-cutting blade to reduce the size. You can build wooden planters with a removable side, making thinning easier. Don’t wait too long. The job just gets more challenging.
Root Barriers
You may have a natural root barrier, such as a rocky terrain or a pond. Despite its tropical appearance, bamboo does not like wet feet. It makes a great companion planting around ponds and will grow best on a small mound, elevating its roots from moisture. You can use a densely forested area as a natural barrier, as bamboo needs some sun. You do not want to plant larger or timber bamboo close to your home, driveway, or sidewalks. Clumping bamboo can also put a lot of pressure on a barrier or pot. Allow room on all sides of the barrier to do maintenance. Don’t install a barrier right on a property line. Set it back about two feet so you can manage the back side.

Most yards do not have suitable natural barriers, so fabricated barriers are needed. Typical bamboo root depth is around 8-12″, with some timber bamboo roots reaching around 18″. A healthy bamboo with vigorous roots will try to dig under or over the top of your barrier, so a barrier height of 24″ is common. Barriers up to 30″ may be required for timber bamboo. If you mound your bamboo, a shallower barrier can work.

You can use metal, wood, or fabric as barriers. Metal will rust and disintegrate over time, and wood will rot. The most long-lasting barriers are either rigid 40 mil HDPE (high-density polyethylene) or flexible EPDM (ethylene propylene diene monomer). Alternatively, you can buy a thick EPDM pond liner and cut it to size. Standard landscaping fabric is insufficient for control. You can buy molded pond liners in various shapes and fill them with dirt instead of water. You will need to cut holes in the bottom so they drain, but don’t cut them too close to the sides.

Barriers will do a good job of containing the bamboo, but you still need to inspect the area during the spring and summer and check for the occasional rhizome trying to go over or under the barrier. The bamboo stand will overgrow its area over 3-7 years and must be thinned. It is best to do this before the roots become a solid mass and are hard to cut. Plan on removing a third of the bamboo every 3 years. Battery-operated or electrical reciprocating saws with long wood or pruning blades make the job easier.

Perimeter Trench
Another method of containment is a loosely filled perimeter trench. Dig an 18″ deep trench about 12-18″ wide around the bamboo location. Fill it with sand, pea gravel, or loose soil. Don’t use soils with silt or clay, as they will compact and harden over time. Bamboo rhizomes will continue to grow and expand freely when they enter the trench. In the fall or early spring, use a spade (the ones with serrated blades work best), root saw, or reciprocating saw with a long blade and work around the perimeter, cutting off and removing any new growth that has entered the trench. Make sure to pull out all of the rhizomes. You do not need to worry about the fibrous roots.

Fargesia nitida ‘Jiuzhaigou’is a clumping bamboo. This cultivar is ‘Red Fountain’ with red canes. Many cultivar of this variety can be found with different colored canes. © Photo by Kay Torrance

Fargesia robusta ‘Campbell’ is a clumping bamboo with ¾” canes. © Photo by Kay Torrance.

Removing Shoots and Mowing
Another method of control is simply removing unwanted shoots at the ground level or just below. It is easiest to do in the spring when they are tender. They will not grow back. For smaller-diameter bamboo, you can use your lawn mower to run over unwanted culms anytime.
Pruning the Foliage
Bamboo foliage doesn’t need a lot of maintenance. Varieties with many horizontal branches can be legged up to showcase the culms better. If you need to control the height, bamboo is very tolerant of topping. However, it saves work to choose the right-sized bamboo for your location. 

You should thin the canes every year or two. If the canes are not thinned, the grove can become very dense and vase-shaped as culms compete for sunlight. Cut the canes anytime during the year at or below ground level, removing no more than a third of the canes each year. New canes are not as strong, so thin the oldest canes. Old canes have many uses, so think of this as harvest time.

Rejuvenation or Removal
Rejuvenation often requires removing a large portion of the bamboo grove. The easiest way to kill all or part of the plant is to remove the unwanted canes at ground level or just below it and not let them grow back. Remove bamboo with small-diameter canes with a lawn mower; larger canes will require a lopper or a saw. 

Bamboo needs nourishment from the canes and will die without it. It is best to use this method right after the new culms have reached full height in early summer. The plant has just expended a great deal of energy sending up the culms and will be severely weakened by pruning. It will try to regrow, so make sure to follow up. It can take one to three years before the plant is completely dead. Make sure to shut off irrigation and sprinklers in the area. This method leaves the roots in the ground but they will rot in a year or two.

If you need immediate removal of the plant and rhizomes, the only solution is digging. It is best done when the soil is moist. Cut the canes at one foot (or so) above the ground and use them to help pull out the rhizomes. Get all the rhizomes, but don’t worry about the fibrous roots. As for other methods, there are many: applying chlorine, salt, vinegar, and even gasoline. These contaminate the soil. They may kill the bamboo, but they will destroy the soil ecology and everything nearby. 

Fargesia dracocephala ‘Rufa’ ‘Dragon’s Head’ at the WSU Discovery Garden. This clumping bamboo has a loose weeping habitat so the hedge has been pruned to keep it off the path. Bamboos tolerate pruning well as long as adequate leaves are left for plant health. © Photo by Kay Torrance

Purchasing Bamboo
If you are still reading and anxious to start, don’t rush out and buy the first plant you find. Many nurseries carry only one or two varieties of bamboo. Often, they choose varieties that grow fast and are easily divided, which may not be what you want. 

When choosing plants:

• Avoid plants that are pot-bound with circling roots. These plants will usually have the culms growing right next to the outer edge of the pots, and sometimes, the pots will bulge where the rhizomes are overcrowded.
• Like most plants, a larger pot with more mature culms will establish quicker than a recently divided plant with one or two culms.
• Pay attention to the label. Expect that it will take 3-5 years for plants to reach its established height. The old adage about the first year a plant sleeps, the second it creeps, and the third it leaps is very true of bamboo. It is normal for nursery wholesalers to prune the stalks when dividing or transporting stock, so don’t go by what you see for height.
• Check the label for growing zones. Cold tolerance is important. Some lovely bamboos are marginal for our area. A hard, prolonged freeze might kill them, or they may die down to the ground. If the rhizomes survive, they can take years to recover.

If you can’t find what you want locally, consider mail order. Many bamboo specialty nurseries and Japanese botanical gardens have groves of mature plants for reference. Do research online. There are lots of pictures of bamboo staged with a person for scale. Plan to plant your bamboo in the spring or early summer to establish roots before any freezes. For the first summer, bamboo needs regular water and heavy mulch.

Variety Suggestions

• Fargesia nitida ‘Jiuzhaigou’ is a short and slender clumping variety of bamboo that grows 8-10′ tall. Many colorful cultivars are available, such as ‘Red Fountain’ and ‘Black Cherry’. The canes are pencil-thin with tiny leaves. It has a dramatic vertical growth habit and is very manageable both individually and as a hedge.
• Fargesia rufa ‘Sunset Glow’ is a small clumping bamboo that grows 5-10′ tall with 1/3″ red-orange canes, medium-sized leaves, and a weeping growth habit. Suitable as a shrub in a grouping or a short, dense hedge to provide color.
• Fargesia dracocephala ‘Dragon’s Head’ is a clumping bamboo that grows 8-12′ with 1/2″ canes. It also has a weeping fountain-shaped appearance with medium-sized leaves that sway in the wind. Good for a dense hedge, but allow room for it to lean.
• Fargesia robusta ‘Campbell’ is a clumping bamboo that grows to 12-15′ with ¾” canes. The canes start green but age to a pale yellow. Very upright and tight culm spacing with large leaves. Makes a very dense hedge or large 15-20′ grove. It tends to become vase-shaped if culms are not thinned to allow light to reach the center. Canes are straight and strong.
• Qiongzhuea tumidissinoda, known as ‘Walking Stick’ bamboo, has ½” canes with enlarged nodes. It is only recommended for containers as it is an aggressive and agile runner. It grows 10-15′ but less in containers.
• Pleioblastus viridistriatus is commonly called ‘Greenstripe’ bamboo. It is widely available and grows 2-3′ with tiny canes. It has chartreuse and cream-colored variegation in the leaves. It is unusual because it is deciduous, losing its leaves in the winter. It is a great container plant or tall ground cover. Due to its small size, many people control it with their lawnmower instead of barriers or pruning.

Finally, if you are looking for the impact of a bamboo forest, look for a medium-height running bamboo to plant inside a barrier or container. The iconic Phyllostachys nigra ‘black timber’ bamboo is a good choice. However, the variety is currently undergoing a mass flowering event. Bamboos only flower every 30-120 years, depending on the species. After flowering, the entire plant dies. Since most bamboo is propagated by division, the plants of a particular variety are all identical. They will die en mass worldwide until they return from the notoriously tricky seeds to germinate. That is what is happening now with the beloved black bamboo. For now, if you are looking for the aesthetics of a timber bamboo, try one of the Phyllostachys. The variegated Phyllostachys aureosulcata ‘Yellow Groove’ is a good choice that sports an occasional zigzag cane or perhaps the classic Semiarundinaria fastuosa ‘Red Temple’, for more color.

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RESOURCES:

Heinricher, J. and Flemmons, K. (2006) Discovering Bamboo. Boo-Shoot Gardens LLC

Meredith, Ted Jordan (2006) Timber Press Pocket Guide to Bamboos, Timber Press, Portland, OR

Farrelly, D. (1984) The Book of Bamboo: A Comprehensive Guide to This Remarkable Plant, Its Uses, and Its History.Sierra Club Books, San Francisco, CA

Stangler, C. (2001) The Craft & Art of Bamboo. Lark Books; New York, NY

American Bamboo Society. https://www.bamboo.org

WSU Vegetable Research and Extension. https://vegetables.wsu.edu/crops/bamboo/

 

AUTHOR:
Kay Torrance has been a Skagit County WSU Extension Master Gardener since 2019. She is garden coordinator of the Naturescape garden and pond in the Discovery Garden on SR 536 west of Mount Vernon. https://www.skagitmg.org/home/discovery-garden/

Enjoy a Day Trip to Tour a Pacific Northwest Garden

February is an excellent time to look ahead and plan a visit to one of the many public gardens showcasing a range of plants from native to tropical beauty

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By Skagit County WSU Extension Master Gardeners

Creating and appreciating a garden is a dynamic, creative process that benefits from the inspiration of others’ work, traditions, and history. Gardeners in the Pacific Northwest are fortunate to have access to many garden styles and a wide variety of plant combinations at gardens and nurseries that are open to the public – all within range of a day trip from Skagit Valley.

In this article, several Skagit County WSU Extension Master Gardeners share observations from their recent visits to a sampling of regional display gardens. Each author highlights the visit with inspirations ranging from the native rhododendrons of Meerkerk Gardens on Whidbey Island to the amazing cloud forest of the Seattle Spheres.

Perhaps you are hosting visitors this summer or in charge of planning an outing for a group of friends; use these ideas as a springboard for your next garden inspiration. Details for each garden include website links, contact information, logistics, and admission information to help prepare for a visit.

University of Washington Biology Greenhouse Photo © Kay Torrance

University of Washington Biology Greenhouse Photo © Jessamyn Tuttle

University of Washington Biology Greenhouse

Location: Lower level, southwest side of the Life Sciences Building, at 3747 W Stevens Way NE, Seattle, WA. Map

By Kay Torrance, Skagit County WSU Extension Master Gardener

In 2023, a group of Skagit Master Gardeners toured the UW Biology Greenhouse, the Elizabeth C. Miller Library, the UW Botanic Gardens and the Washington Park Arboretum. Though this excerpt focuses on the biology greenhouse, I recommend each of the venues as a treasure trove of plant learning,

The UW Biology Greenhouse is a 20,000-square-foot facility opened in 2022, showcasing over 6,000 plant species. According to the website, the new structure “replaces the original Botany Greenhouse, where the UW’s biology department had amassed one of the country’s most diverse plant collections over a period of 65 years.” Led by docents, the group explored four themed garden rooms: Desert, Tree of Life, Warm Tropics, and Cool Tropics.

The Desert Room features North American cacti and plants from Africa, including a Welwitschia from Namibia. Next, the group walked through the Tree of Life room, where plants are displayed in evolutionary order. Next, the tour moved into the warmth of the Warm Tropics Room, filled with palms, gingers, and orchids. The tour then took the Master Gardeners to the Cool Tropics Room, showcasing high-altitude tropical plants. The greenhouse also includes climate-controlled rooms for research and education, benefiting university students in fields such as plant ecology and landscape architecture.

Read an entire blog article about the 2023 visit to the UW Biology Greenhouse at https://www.skagitmg.org/visit-uw-botanic-garden/

Website: https://www.biology.washington.edu/facilities/greenhouse

Hours and tours:

• The UW Biology Greenhouse is open to the public from noon to 4 p.m. on non-holiday Wednesdays and 10 a.m. to 2 p.m. on the second and fourth Saturdays of the month-docent-led tours for groups of more than eight people by arrangement.
• The UW Botanic Gardens and Washington Park Arboretum are open daily to the public. https://botanicgardens.uw.edu/

Admission: Free

Contact information: https://www.biology.washington.edu/facilities/greenhouse/contact

The Seattle Spheres

Location: 2111 7th Avenue, Seattle

By Laura Kuhn, Skagit County WSU Extension Master Gardener

The Seattle Spheres is a private biosphere space created at Amazon headquarters near downtown Seattle in 2018. The space, which includes three glass-enclosed spherical conservatories, is open by reservation only to the public on the first and third Saturdays of each month.

This lush and beautiful facility supports a cloud forest environment – think rainforest tree canopy – supporting flora ranging from tiny begonias and orchids to large tree ferns and aloes. A highlight is the “living walls” that boast over 25,000 plants woven into 4,000 square feet of mesh in what the organization calls an “innovative demonstration of biodiversity.” Trees are planted in pots in the Canyon Living Wall area, and the vertical gardens are more than three stories tall.

There are over 40,000 plant varieties, with many plants in bloom in a wide range of colors, shapes, and sizes. Visitors may explore four stories of plants accessible by stairs or elevators.

Website: Seattlespheres.com

Hours: By reservation only, open to the public from 10 a.m. to 6 p.m. on the first and third Saturdays of each month. If you do not have a reservation or go to the location on another day of the week, visit the Understory or the Urban Arboretum found outside of The Spheres.

Admission: Free

Contact Information: For details and to make a reservation, go to https://www.seattlespheres.com/the-spheres-weekend-public-visits

Chihuly Garden and Glass

Location: 305 Harrison Street, Seattle

By: Kathy Wolfe, Skagit County WSU Extension Master Gardener

Chihuly Garden and Glass highlights a beautiful combination of the iconic glass works of artist Dale Chihuly set in a vibrant garden showcase. The Glasshouse and adjacent displays and exhibitions opened at the base of the Space Needle in Seattle Center in May 2012.

The stunning Chihuly glass art, coupled with beautiful gardens, is a collaboration that inspires visitors from around the world. Chihuly has worked with public gardens – large and small – in the US and internationally to create colorful blends of plants and glass that meld into complementary natural vignettes. Gardeners can be inspired by the clever combinations of glass and plants.

Depending on the time of year, visitors to the Glasshouse may see a wide range of camellias blooming among dogwood, along with scarlet daylilies and fuchsias, accented by icicle-shaped glass towers and spheres incorporated to embellish the scene. The gardens are transformed seasonally, and a master plant list used by the landscape design team is available on the facility’s website.

In addition to the garden area of the exhibit, ticket prices include the Exhibition spaces containing Chihuly’s glass creations, drawings, large architectural installations, and personal collections. A theater offers a short film on Chihuly’s artwork; a free audio tour is available. The Bar restaurant provides food and beverages; and a bookstore offers a selection of gifts, cards, and books.

Website: https://www.chihulygardenandglass.com

Hours and tours: Hours vary daily, so check the website for details. The venue can be closed for private events. Highlight tours are offered three times daily and included in the price of admission.

Admission: Tickets should be purchased in advance. Prices range from $22 to $37.50 depending on a guest’s age (free for children under four) and the time of year.

Contact Information: For general information, call 206-753-4940 or contact [email protected]

Happening now: “Winter Brilliance” is a light and music installation containing more than 700 hand-blown glass forms that runs until February 28, 2025, in Gallery 1.

Elizabeth C. Miller Botanical Garden Photo © Crowell Photography.com

Elizabeth C. Miller Botanical Garden
Photo © Crowell Photography.com

Elizabeth Carey Miller Botanical Garden

Location: 79 Olympic Drive Northwest, Seattle

By Nancy Crowell, Skagit County WSU Extension Master Gardener

In Western Washington gardening history, there are a handful of people all serious gardeners should know about because of their incredible, prolonged influence on gardening in the region. One of those people was devoted horticulturist Elizabeth C. Miller, whose name is now associated with the Elizabeth Miller Library at the UW Center for Urban Horticulture and the Elizabeth Carey Miller Botanical Garden – commonly known as the Miller Garden.

The Miller Garden, which was developed on six acres of Miller’s private home, has established collections and themed areas. However, the key to why a diehard gardener should take a tour here is that this garden is where Great Plant Picks tests and chooses the plants recommended for our Pacific Northwest gardens. The garden’s website describes the Great Plant Picks as “recommendations for a comprehensive palette of outstanding plants for the maritime Pacific Northwest.” The website states that more than 1,000 plants have been selected to date for gardeners living west of the Cascade Mountains from Eugene, Oregon, to Vancouver, British Columbia.

The garden was designated a public garden in trust after Miller died in 1994, unbeknownst to her neighbors in the exclusive neighborhood. As a compromise to neighbors concerned about large numbers arriving in the neighborhood, the garden is limited to 500 visitors a year, and the coveted entry tickets are sold out months in advance. In fact, the entire 2025 tour season is already sold out.

The garden is well established, yet still a work in progress as caretakers update and refresh the original plantings. A tour reveals surprises around every corner. Fall is a favorite time to visit due to the vast collection of established Japanese maples, though a midsummer visit was equally impressive.

Miller and her horticultural adventures are fascinating. Read more at https://millergarden.org/, then toss your name into the tour lottery. I hope you get a call.  

Website: https://millergarden.org/

Hours and tours: All visits to the Miller Garden are by reservation only with a staff member as a guide. The garden website states, “due to an unprecedented response, the 2025 tour season is now filled.” Early bird reservations for 2026 will open in autumn 2025. A “virtual” tour is offered online at https://millergarden.org/the-garden/

Admission: Free

Contact Information: To be added to the email list for class or tour date announcements, send a message to [email protected]

Heronswood Photo © Heronswood

Heronswood
Photo © Heronswood

Heronswood

Location: 31912 Little Boston Rd NE, Kingston, WA Note: Ferry wait times to the Olympic Penninsula can be long so make reservations and plan accordingly.

By Anne Hays, Skagit County WSU Extension Master Gardener

Nestled in the charming town of Kingston on the north end of the Olympic Peninsula, Heronswood Garden can feel like stepping into a living dream. This enchanting botanical garden, established by renowned plantsman Dan Hinkley, is a paradise for anyone who cherishes nature’s quiet beauty.

The gardens opened in 1987 and comprise 15 acres and more than 8,000 varieties spread across six distinct yet integrated gardens.

As guests pass through the garden gate, they are immersed in a world where every path leads to a new discovery. Heronswood’s collection of rare and unusual plants is astounding, curated from all corners of the globe. The garden’s thoughtful design blends exotic with native plants, creating a seamless tapestry of textures and colors that change with the seasons.

The garden bursts to life in spring, with rhododendrons in full bloom in a variety of vibrant hues contrasting with the surrounding lush greenery. A fern glade mesmerizes visitors with the delicate interplay of light and shadow.

As one of the state’s “hidden gems,” the gardens offer tranquility and intimacy, allowing guests to wander for hours enjoying the color, listening to the birdsong, and gaining inspiration.

For some visitors, Heronswood is more than a garden-it’s a haven. For plant lovers, artists, and anyone seeking solace in nature, it’s a destination that lingers in the heart long after.

Website: https://www.heronswoodgarden.org/

Hours: 9 a.m. to 3 p.m. Saturday and Sunday. Closed major holidays. Summer opening hours start April 2, 2025.

Admission: $10 for adults, $5 for youth aged 7 to 17, and free for children aged 6 and younger. 

Contact Information: 360-297-9620, [email protected]. To learn more about classes and events, go to https://www.heronswoodgarden.org/event

Meerkerk Gardens

Location: 3531 Meerkerk Lane, Greenbank, WA (Whidbey Island)

By Anne Hayes,  Skagit County WSU Extension Master Gardener

Nestled just 50 miles from Mount Vernon is Meerkerk Gardens, described as a well-curated “peaceful woodland garden.” The grounds provide a conveniently accessible garden, one of Whidbey Island’s best-kept secrets.

Established by Ann and Max Meerkerk, the grounds include a 10-acre Northwest woodland display garden and 43 woodland acres lined with nature trails. The gardens showcase native flora, including rhododendrons, azaleas, and companion plants, in a variety of garden rooms. Visitors may stroll along the curving, easy-walking paths through the splendor of rhododendrons galore – featuring vibrant shades of colors from white to pink and vibrant red to purple. Today, the Meerkerk Rhododendron Garden nonprofit manages the gardens and woodlands, established in 2002.

In addition to garden access, the website offers detailed information about seasonal guided walks, concerts, children’s programs, nature classes, rhododendron care classes, and guided tour information. The website also features a bloom report so guests can time a visit to experience the complete joy and bloom of the gardens. The garden features color and texture during all seasons.

A special addition is the onsite nursery, open by appointment only in the fall and winter months, reopening in March on Friday, Saturday, and Sunday.

Website: [email protected]

Hours: Open 9 a.m. to 4 p.m. daily

Admission: $10 for adults and free for children under age 13. Dogs on leash are welcome.

Walks: Guided walks are offered during some seasons, starting at 1 p.m. at the Gatehouse and lasting about 90 minutes. Walks are free for Friends of Meerkerk (and children under 13); the cost is $15 per person for non-members.  Preregister at www.meerkerkgardens.org/events

Contact Information: 360-678-1912

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Is there a garden you love or hope to visit soon?
Share your favorite display gardens in the comment section below.

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Urban Meadow at Bellevue Botanical Garden Photo © James Gagliardi, Bellevue Botanical Garden Director

Yao Garden at Bellevue Botanical Garden Photo © James Gagliardi, Bellevue Botanical Garden Director

Bellevue Botanical Garden

Location: 12001 Main St., Bellevue, WA

By Diana Wisen, Skagit County WSU Extension Master Gardener

As one of the most beautifully designed public botanical gardens in the United States, the Bellevue Botanical Garden is a “must-see” for anyone who loves gardens in the Pacific Northwest. The garden spans 53 acres in a wondrous mixture of cultivated gardens, restored woodlands, natural wetlands, and native plant collections. The paths lead visitors through hillside rock gardens, ponds, and a stream, through forests, past a gnome door hidden under a tree, and a Chinese garden, all with lovely works of garden art throughout.

Visitors will likely see varieties of trees they have never seen before. Visitors may wish to bring a cell phone to use the QR codes on the signage for more educational information about the plants. A small professional staff maintains and manages the garden along with local groups and individuals who donate nearly 20,000 hours a year to maintain the gardens.

The garden is known for its winter light display called “Garden d’Lights” during December, with tickets sold online.

The garden is currently hosting a special traveling exhibit called “The Lost Birds” through September 2025. The display features hauntingly beautiful giant bronze statues of extinct birds placed in a circle.

The Trillium Store gift shop and Copper Kettle Coffee shop both have seasonal hours.

Website: https://bellevuebotanical.org/

Hours and tours: Open daily from dawn to dusk, including all holidays. Free public tours are available on Saturday and Sunday, April through October. Private docent-led group tours can be scheduled online.

Admission: Free. Service animals are only allowed in the garden.

Contact Information: Administrative Office may be reached at 425-452-2750. To contact the Bellevue Botanical Garden Society, email [email protected]

Skagit County WSU Extension Master Gardener Discovery Garden

Location: 16650 State Route 536 (Memorial Highway), Mount Vernon, WA

By Ginny Bode, Skagit County WSU Extension Master Gardener

The Skagit County WSU Extension Master Gardener Discovery Garden, located on State Route 536 west of Mount Vernon, always amazes visitors. A stop at the gardens is an easy addition to the list of area attractions.

First-time visitors are often surprised by the extensive collection found in the 1.5-acre garden. The well-maintained paths wind through 25+ garden rooms, including a koi pond, an herb garden, a vegetable garden, and many benches for resting. Each garden has a focus on specific plants that thrive in the Skagit Valley.

Visitors will find many educational opportunities and kiosks about growing fruits and vegetables, ornamental and native plant gardening, pollinators, and composting.

A highlight is the Children’s Garden, which is filled with colorful plants and whimsical structures. It is a place where children can touch, smell, and explore different textures, as well as vegetable patches and flower beds that encourage curiosity about how food grows and foster a love of nature and gardening.

The Discovery Garden, designed to inspire and educate the public, is maintained by 150 volunteer master gardeners. An annual open house is held in the garden from 10 a.m. to 2 p.m. on the last Saturday in June, featuring a plant clinic and children’s activities.

Adjacent to the Discovery Garden are two additional public display gardens on the WSU NWREC property: the 0.5-acre Salal Native Plant Garden and the 6-acre NW Fruit Garden.

Website: https://www.skagitmg.org/home/discovery-garden/

Hours: Open daily during daylight hours

Admission: Free

Contact Information: For information, go to https://www.skagitmg.org/home/discovery-garden/

THANK YOU TO THE AUTHORS:
Kay Torrance, Laura Kuhn, Kathy Wolfe, Nancy Crowell, Anne Hays, Diana Wisen, and Ginny Bode with the introduction by Kari Ranten. All are Skagit County WSU Extension Master Gardeners who love visiting and finding inspiration in display gardens near home or on holiday.

Hummingbirds in the Garden: Food Sources and Benefits

Food sources for resident Anna’s and migrating Rufous hummingbirds and tips for safely hosting a feeder in your garden.

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By Joan Stamm, Skagit County WSU Extension Master Gardener

There’s a wealth of information out there about our beloved hummingbirds-fascinating mythology, a horrifying feather trade history, descriptions of dazzling aerial dynamics, and arduous migratory habits-but this article will focus on beneficial food sources for our resident Anna’s and migrating Rufous, as these hummingbirds are not only an important part of our ecosystem that helps control insects, but are great pollinators. If this weren’t enough, they are simply a delight to watch.

Let’s start with the basics:

In early spring, Anna’s hummingbird finds nectar in the red-flowering currant (Ribes sanguineum) © Photos: Mason Maron | Audubon Society 

Insects and Spiders
The least glamorous but one of the most important hummingbird food sources is insects. Female Anna’s, when raising their young, can eat up to 2,000 bugs per day. In fact, Douglas Tallamy, a professor of entomology at the University of Delaware, claims that although “Hummingbirds like and need nectar … 80 percent of their diet is insects and spiders.”

Native trees and shrubs, more than “introduced” varieties, provide the highest potential for attracting native insects. To ensure a steady supply of native invertebrates that all birds, but especially hummingbirds, enjoy, plant a variety of native plants in your garden. Another way to increase insect populations is to leave the leaves in the fall. Many insects hide and winter in leaf litter. Instead of tidying up and throwing all those wonderful leaves in the compost bin, pile them up around your plants and postpone cutting away all the dead flower debris until spring. These practices will increase your insect population, and hummingbirds will help keep your bugs in check.

Make the choice to avoid pesticides.
Pesticides containing neonicotinoid insecticide are widely used by farmers and homeowners, and on pets for flea and tick treatments. Even though neonicotinoids are relatively less toxic to beneficial insects and pollinators, and their use is supported by WSU and USDA, many gardeners prefer to avoid their use. Some research institutions have found that hummingbirds exposed to systemic neonicotinoid insecticides for even a short time can disrupt their high-powered metabolism. Hummingbirds are pollinators. They can visit hundreds of flowers in a day. Any pesticide that can harm bees will likely harm hummingbirds.

 

Though not native to the Pacific Northwest, the brilliant red flowers of Crocosmia ‘Lucifer’ attracts hummingbirds throughout the summer. © Photo: Nancy Crowell | crowellphotography.com

 The Rufous hummingbird is attracted to ‘Black & Blue’ anise sage (Salvia guaranitica) © Photo: Phil Green | philgreen.net

Tree Sap
We don’t often think of tree sap as being an important food source for birds, but when flower nectar is scarce our migrating Rufous hummingbird will turn to sap in tree wells left by red-breasted sapsuckers and woodpeckers. If your garden can accommodate aspen, birch, or pine, you will create another potential food source for our Western Washington hummingbirds; plus providing important nesting and perching habitat.
Native and Non-native Flowers
Along with the protein, fats, and amino acids found in insects and the minerals found in tree sap, other nutrients important to hummingbirds are found in flower nectar. “Scientists have learned that the richness of the nectar matters more than the color of its source,” which in most cases would come from plants native to our region. A perfect example is our native snowberry (Symphoricarpos albus) which has tiny pink (not red) flowers that hummingbirds return to again and again. They also like our native nodding onion (Allium cernuum) with its tiny pinkish mauve flowers. Even osoberry (Oemleria cerasiformis), with its white pendulous flowers, offers good quality nectar early in the season as they are one of the first native trees to bloom.

But if you want to give hummingbirds their preferred red-orange range, try our native red paintbrush (Castilleja miniata), western columbine (Aquilegia formosa), red-flowering currant (Ribes sanguineum), Cascade penstemon (Penstemon surrulatus), and hot pink and scarlet monkeyflower (Mimulus lewesii and cardinelli) to name a few.

Along with natives, and to ensure a steady supply of flower nectar throughout the year, there are many introduced varieties that hummingbirds love. Most notably in my garden are the salvias- ‘hot lips’ and ‘black and blue.’ They also like bee balm, crocosmia, fuchsia, and weigela. For winter bloomers, Ciscoe Morris, the NW gardening guru and host of “Gardening with Ciscoe” recommends witch hazel, Camellia sasanqua ‘Yuletide,’ sweetbox, Daphne odora, Viburnum x bodnantense ‘Dawn,’ Grevillea victoriae, and the Asian hybrid Mahonia x media.

During breeding season, the hummers helicopter from plant to plant until they get their fill, mixing nectar with insect protein to feed their young, which is strictly the female’s job, along with nest building. The males resume their independent lifestyle.

Western columbine (Aquilegia formosa) is native in our area and provides food for Anna’s hummingbird © Photo: Phil Green | philgreen.net

Many enjoy feeding hummingbirds, but doing so comes with the responsibility of keeping the feeders clean and free of bacteria to avoid harming the birds. It may be easier to grow native plants such as snowberry and red currant to help the hummers through late winter. © Photo: Nancy Crowell | crowellphotography.com

Hummingbird Feeders
If you are going to use hummingbird feeders-and it’s really the overwintering Anna’s that mostly benefit as the Rufous is long gone by the end of summer-then the overwhelming advice from experts is that feeders be clean, clean, and clean. Some say feeders should be cleaned every 3 to 4 days, some say 5, and others say if the weather is above 65 degrees, they should be cleaned daily to prevent the sugar water from fermenting. “Sugar water is a nursery for bacteria, mold, and potentially dangerous pathogens.” Fermented sugar water can enlarge a bird’s liver imperiling its health. “Ten percent or more of the hummingbirds who wind up in rehabilitation centers have yeast infections from improperly maintained feeders.” Clean feeders with hot, soapy water or vinegar. Never use bleach as any residue is not only toxic to birds but to the environment in general.

The recipe for the sugar solution is one part plain white non-organic refined sugar to four parts water. Do not use red coloring or any commercial product with chemicals or dye. Boil the solution, let it cool, and fill your feeder. Hang more than one feeder to avoid competition. Hang them away from a window to prevent hummingbirds from flying into the glass and breaking their neck. In summer, hang them in the shade. In winter, hang them in the sun. If temperatures drop, you will need to rig up a heating element to keep the solution from freezing or rotate your feeders throughout the day. If all this sounds like too much work and responsibility-inadvertently harming hummingbirds rather than helping-it might be easier to grow a variety of nectar-rich flowers instead and leave the rest to nature.

 

Learn from the experts at the
Country Living Expo
& Modern Homesteading
Saturday, January 25, 2025
Stanwood High School 

Learn More and Register Here >>

These Gardening Topics and More:

• Fruit Tree Pruning
• Microclimates in the Garden
• Garden Design
• Roses
• Bee Keeping
• Growing Vegetables, Herbs and Flowers
• Tool Care and Maintenance
• Small Fruits: Elderberry and Blueberries
• Growing Lavendar

https://extension.wsu.edu/skagit/countrylivingexpo/

Mahonia x media, pictured here, is an Asian hybrid that blooms in winter. Several native Mahonias also attract hummingbirds and bloom in early spring. © Photo: Nancy Crowell | crowellphotography.com

 

The coastal hedgenettle (Stachys chamissonis) is a native plant in the Pacific Northwest that thrives in moist soil near forests and provides support to birds, bees and butterflies. © Photo: Nancy Crowell | crowellphotography.com

 

REFERENCES AND RESOURCES:

BOOKS:

• Link, R.Landscaping for Wildlife in the Pacific Northwest. Washington Department of Fish and Wildlife. 1999
• Shewey, J.Hummingbird Handbook. Portland: Timber Press. 2021
• Stark, E. M..Real Gardens Grow Natives. Seattle: 2014
• Tallamy, D.Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard. Portland: Timberpress. 2019

ON-LINE:

• All About Birds –https://www.allaboutbirds.org/guide/Annas_Hummingbird/
• Beyond Pesticides: https://beyondpesticides.org/dailynewsblog/2021/02/hummingbirds-are-being-harmed-by-the-same-pesticides-killing-off-bees-butterflies-and-other-pollinators/
• Georgia Department of Natural Resources:https://georgiawildlife.com/out-my-backdoor-beyond-hummingbird-feeder.
• The Humane Gardener: https://www.humanegardener.com/a-fighting-chance/#:~:text=Hummingbirds%20are%20more%20visible%20to,in%20our%20yards%20as%20well.%E2%80%9D

ABOUT THE AUTHOR:

Joan D. Stamm, is a certified Skagit County WSU Extension Master Gardener and the author of several books, including The Language of Flowers in the Time of COVID:  Finding Solace in Zen, Nature and Ikebana.

 

 

Red-twig dogwood (Cornus sericea) © Joan D. Stamm

Gardening for Wildlife

Thinking of adding new plants to your garden this spring? Choose from these recommendations to build a healthy ecosystem for your favorite wildlife species.

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Updated: August 18, 2024

By: Joan D. Stamm, Skagit County WSU Extension Master Gardener

In a blog article last September, I recommended reading Nature’s Best Hope by Douglas Tallamy for the “why” of gardening for wildlife. This article will explore the “what” and the “where”-as in “what” plants and “where” to buy them.

For the “what,” I suggest Real Gardens Grow Natives by Eileen M. Stark as a guide to site prep, plant selection, and the benefits each plant offers the ecosystem. “Benefit” in this article, as in Stark’s book, is the critical word. It points to what the National Wildlife Federation (NWF) has coined as keystone plants.

What exactly is a keystone plant?
According to NWF, keystone plants are “native plants critical to the food web and necessary for many wildlife species to complete their life cycle. Without keystone plants in the landscape, butterflies, native bees, and birds will not thrive. 96% of our terrestrial birds rely on insects supported by keystone plants.”

Stark, a wildlife conservationist and landscape designer from Portland, Oregon, specializes in wildlife habitat gardens that include keystone plants. In the 317 pages of her beautifully photographed book, you will find 100 of her favorite Northwest native plant varieties and their many benefits for wildlife.

Yarrow (Achillea millefolium) © Joan D. Stamm

Twinberry (Lonicera involucrata) © Joan D. Stamm

Snowberry (Symphoricarpos albus) © Joan D. Stamm

For example, the Garry oak or Oregon white oak (Quercus garryana) is one of the top keystone plants Stark promotes in her book. If we want butterflies in our garden, we need to have trees, shrubs, and perennials that host butterfly larvae. The Garry oak is one such tree; it is a host plant for many caterpillars, including the “gray hairstreak, California sister, and Propertius duskywing butterfly larvae.” In addition, the “flowers attract native bees,” and the “acorns sustain populations of mammals and birds such as woodpeckers, nuthatches and vireos.” “Studies show,” writes Start, “that oaks support more insect herbivores than any other plant genus.”

Although incredibly beneficial, not everyone has space for an 80-foot Garry oak. If not, consider another keystone tree: bitter cherry (Prunus emarginata). Birds such as “tanagers, waxwings, bluebirds, towhees, and flickers” will arrive to eat the fruit. A native cherry also hosts “swallowtail and Lorquin’s admiral butterfly larvae.”

If you love butterflies, another great keystone tree is Scouler’s willow (Salix scouleriana); it hosts “western tiger swallowtail, great comma, dreamy duskywing, and mourning cloak butterfly larvae.” In addition, native willow flowers “provide pollen and nectar for bees,” and “small and large mammals feed on buds, leaves, and seeds.”

Kinnikinnick (Arctostaphylos uva-ursi) © Joan D. Stamm

Frog on Sneezeweed © Joan D. Stamm

Bumblebee on blanket flower © Joan D. Stamm

Serviceberry (Amelanchier alnifolia) is also a keystone tree, providing “pollen and nectar for large numbers of bees, as well as hummingbird and spring azure butterflies.” Serviceberry fruit, says Stark, “is relished by waxwings, chickadees, woodpeckers, and tanagers,” and it is a host plant for “pale swallowtail, brown elfin, Lorquin’s admiral, and California hairstreak butterfly larvae.”

Along with these important native trees, many keystone perennials can fit into any open sunny space in your garden. A beneficial plant throughout many regions, goldenrod (Solidago canadensis), is a “nectar source for native bees and butterflies, such as the checkered skipper, clouded sulphur, gray hairstreak, monarch [east of the Cascades], and the endangered Oregon silverspot.”

Douglas aster (Symphyotrichum subspicatum) “provides nectar and pollen for bees and nectar for woodland skipper, pine white, painted lady, red admiral, mourning cloak, and the Oregon silverspot.” It is also a “host plant for field crescent and other butterfly larvae.”

Big-leaf lupine (Lupinus polyphyllus) not only “provide[s] pollen for native bumblebees,” it is a “host plant for silvery blue, painted lady, and orange sulfur butterfly larvae. Aphids attracted to the plant are preyed upon by syrphid fly larvae. Seeds are eaten by birds such as sparrows and finches.”

The Viola adunca, a native violet in our state, is a dynamic host plant for at least seven species of butterfly caterpillars and an enticing nectar plant for the endangered Mardon skipper butterfly.

Stark divides her native plant selections into three categories: plants for sun, partial sun, and mostly shade, guiding us in our creed “right plant, right place.” You’ll also find chapters on soil, pruning, watering, weeding, mulching, and much more. Her book is this gardener’s “go-to” choice whenever looking for the right native plant for a particular area and wanting to know the benefit to nature: what bees, butterflies, birds, or caterpillars the plant will attract.

As beneficial as all native plants are for our native wildlife, some natives on Stark’s list may not be suitable for an urban or suburban garden. For example, western red cedar, grand fir, Douglas fir, western hemlock, and Sitka spruce, are all enormously beneficial, but grow to a height of over 100 feet. The Douglas’ spirea, Stark warns, “may be too assertive for small, moist gardens.” Yet, the Spiraea betulifolia var. lucida, a small shrub with white flowers, might be perfect for a sunny border. Be sure to familiarize yourself with height, width, water requirements, and characteristics such as “vigorous,” “assertive,” or “rapid spreader” to determine if you have the “right plant for the right place.” A Nootka rose’s flowers and hips provide many benefits to wildlife but, over time, will grow into a thicket. However, if you have room for it to spread, it might make the perfect hedgerow, providing not only winter food for juncos and grosbeaks but also a habitat for nesting birds and the western checkerspot butterfly caterpillar.

For a more comprehensive book on creating gardens for wildlife, see Russell Link’s Landscaping for Wildlife in the Pacific Northwest. Link’s book not only includes extensive lists of native and non-native plants that benefit wildlife but also illustrates how to build habitats for birds, reptiles, mammals, and all the other creatures that make up a complete ecosystem. For example, he details snag locations and which draw native birds. He describes how to create a cavity in a live tree without killing the tree and thus create a habitat for a woodpecker. The book contains several kinds of fully illustrated brush or rock piles, including how to make them, where to place them, and who will benefit.

For example, Link says that “bushtits, chickadees, dark-eyed juncos, towhees,” and others “will use the inside of a brush pile,” whereas “hummingbirds, robins, and towhees will use the outside of a brush pile. Salamanders, snakes, toads, and turtles,” will use the base of the brush pile. He also covers how to create or construct proper birdbaths, ponds, nest boxes, and bat houses and features detailed drawings to illustrate how to build homes for Mason and bumblebees. Included are eight pages of colored photos depicting NW native mammals, birds, reptiles, amphibians, butterflies, moths, and other insects, describing our native birds and their preferred habitats.

Bee on Sneezeweed © Joan D. Stamm

Scotch bluebell (Campanula rotundifolia) © Joan D. Stamm

With these three books, Nature’s Best Hope, Real Gardens Grow Natives, and Landscaping for Wildlife in the Pacific Northwest, you will be inspired, informed, and guided to provide plants that offer habitat and food (nectar, pollen, insects) for our native wildlife. You will better understand why it’s important to cultivate natives and have a clearer idea of what to plant, thus joining the movement to restore our natural ecosystem.

The only question remaining is “where” to buy all these wonderful beneficial plants?
You can start with our very own Skagit County Master Gardener Foundation’s Annual Plant Fair, which always features a native plant section. The sale occurs the Saturday before Mother’s Day (May 11, 2024) at the Skagit County Fairgrounds in Mount Vernon.

The local Salal chapter of the Washington Native Plant Society (https://www.wnps.org/salal-programs/garden) offers a twice-yearly native plant sale online with pick up at their demonstration garden adjacent to the Discovery Garden. Sign up to get email notifications.

Some of our local nurseries are beginning to carry more native plants. Azusa Gardens in Mount Vernon on Hwy 20 (https://www.azusagardens.com/) keeps expanding its native plant section each season. They feature two- and five-gallon shrubs such as twinberry, ocean spray, snowberry, red-twig dogwood, mountain hemlock, and others. Twinberry (Lonicera involucrata), in particular, is an attractive and beneficial native shrub easily grown with a little shade. It produces yellow tubular flowers attractive to hummingbirds and the berries are eaten by “thrushes, flickers, grosbeaks, and waxwings”; it’s also a host plant for the “snowberry checkerspot butterfly larvae.” Azusa also carries native ferns, and groundcovers such as bunchberry and wild ginger. They also welcome requests for specific plants.

Christianson’s Nursery in Mount Vernon on Best Road  (https://www.christiansonsnursery.com/) has a native plant section and carries one-gallon great camass (Camassia leichtlinii) in spring. They also have vine maple, salal, western red cedar, fir, hemlock, and kinnikinnick. The latter is a perfect groundcover. Kinnikinnick is not only evergreen, but the flowers are popular with bees and hummingbirds; the berries are eaten by “songbirds and many ground-feeding birds,” says Stark. It is also a “host plant for brown elfin and hoary elfin butterfly larvae.”

Plantas Nativa in Bellingham (https://www.plantasnativa.com/) specializes exclusively in native plants. They pack a lot of choices-conifers, shrubs, perennials, ferns, grasses, water plants, groundcovers, and more-into their small corner lot.

A little farther away but worth the drive, a visit to the Pacific Rim Institute (PRI) https://pacificriminstitute.org/ near Coupeville on Whidbey Island will reward you with not only a native plant nursery but a hike through a preserved segment of Washington’s native prairie landscape that contains the endangered golden paintbrush (Castilleja levisecta). PRI’s Nursery specializes in 50 native prairie plants. Many, such as woolly sunflower, red paintbrush, campanula, yarrow, larkspur, and fescue, will thrive in a sunny spot in your garden. Red paintbrush, in particular, is a beautiful, easy-to-grow native when planted with another native-like yarrow, woolly sunflower, penstemon, or blue-eyed grass. Due to its symbiotic nature, paintbrush requires nutrients from a host plant’s roots to survive. It blooms throughout summer, and Anna’s hummingbird loves the red flowers.

PRI also specializes in some unique native bulbs-ookow (Dichelostemma congestum), blue lily (Triteleia grandiflora), and harvest brodiaea (Brodiaea coronaria), that I hope will begin to replace my non-native tulips and daffodils for spring cheer.

With the knowledge and expertise of Tallamy, Stark, and Link, and a little help from our many plant retailers, you will be inspired to garden with native keystone plants that provide food and habitat for our indigenous birds, bees, and butterflies. In our age of endangered plant and animal species, we can be a force for eco-restoration right in our own backyard.

REFERENCES AND RESOURCES:

Link, R. 1999. Landscaping for Wildlife in the Pacific Northwest. Washington Department of Fish and Wildlife.

Stark, E. 2014. Real Gardens Grow Natives. Skipstone, Seattle, WA

Tallamy, D. 2019. Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard. Timber Press, Portland, OR.

ABOUT THE AUTHOR :

Joan D. Stamm is a Skagit County WSU Extension Master Gardener and the author of several books, including The Language of Flowers in the Time of COVID: Finding Solace in Zen, Nature and Ikebana.

https://joandstamm.com/

Questions about home gardening or becoming a Master Gardener may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg

Discover the Skagit Valley Display Gardens Open House

Discover the Discovery Garden, NW Fruit Garden, and the Salal Native Plant Garden

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By Janine Wentworth, Skagit County WSU Extension Master Gardener

June is the beginning of summer blooming, fruit and vegetable growth and early harvests.

Enjoy the summer gardens of Skagit Valley at the Discover the Display Gardens Open House. Skagit Valley is home to 8 acres of display gardens operated by volunteers as a learning resource for the public.

Discover the Display Gardens
Open House

June 24, 2023 · 10 am – 2 pm

Free Admission

• Skagit County WSU Extension Master Gardener Discovery Garden
• Western Washington Fruit Research Foundation
• Salal Native Plant Garden

All three are nestled together in the green fields of the WSU Northwestern Washington Research and Extension Center west of Mount Vernon on HWY 536 (Memorial Hwy.)

While all three of these gardens are open to the public daily, the Annual Open House is focused on educating and inspiring visitors interested in many specific areas of interest, including pollination, water-wise gardening, native plants and raising fruits and vegetables in the Skagit area.

The Discovery Garden
Designed to support Skagit home gardeners by promoting science-based gardening practices, Skagit area WSU Extension Master Gardeners have created 30 garden rooms within the garden, featuring hundreds of plants chosen to flourish in Skagit Valley. Come and spend time with the volunteers who maintain the gardens and learn more about what they grow.

In addition to tours of the garden rooms, Master Gardeners will be on hand offering activities for all ages including:

• Free garden tool sharpening
• Solutions to plant problems
• Plant identification– to help you know what you have
• Expert advice on weed identification and management

While at the Discovery Garden, visit the small fruits garden and learn more about food you can grow in your own back yard. Photo © Nancy Crowell Photography

Visit the learning station near the pond in the Naturescape Garden. There you will see Koi fish and learn about pond maintenance and construction as well as drip irrigation.

Bring a blanket and picnic lunch and enjoy the day at the Discovery Garden. Photo © Nancy Crowell Photography

Learn about effective gardening at the 8 education stations located throughout the garden area. Master Gardeners will offer instruction on topics such as:

• Developing healthy soil
• Composting
• Pollinator support
• Fruit tree pruning and thinning
• Gardening with native plants
• Weed identification: Match examples of common weeds with their names so you can learn how to identify them and control them
• Clean water and water conservation: Visit the learning station near the pond in the Naturescape Garden. There you will see Koi fish and learn about pond maintenance and construction as well as drip irrigation

Pollinators: Learn about plants that support pollinators from Master Gardeners who plant and care for the pollinator gardens and the pollinators that live in the garden. The pollinator station at the Open House will teach ways to help native bees and other pollinators thrive in home and community landscapes because pollination is an essential survival function.

Local Food: The Skagit County WSU Extension Master Gardeners offer extensive resources for local gardeners. During the Open House, Master Gardeners will be giving talks on healthy soils, growing your own vegetables, and weed identification and eradication. The Grow Your Own Food page at https://www.skagitmg.org/home/resources/food/ is also an excellent resource for gardeners getting started.

While at the Discovery Garden, visit the Vegetable, Small Fruits, and Doc’s Arbor garden rooms for ideas and examples of food-producing plants that grow well in the Skagit County area.

Educators from the Xerex Society will be at the Open House demonstrating techniques for making your garden pollinator friendly

Learn smarter vegetable gardening tips from the Master Gardeners who have research and tested a variety techniques that face gardeners in the North Puget Sound area.

Throughout the growing season, garden waste is sorted, chopped, and chipped– the browns and greens are com­bined and turned, giving us nutrient-rich compost in a few months.

Composting: Curious about how to get started composting? Composting reduces waste and provides an inexpensive treatment for home gardens and landscapes. Healthy soil is essential to have healthy plants. Come talk to our soil experts and learn about your soil and what you can do to improve it.

Growing the Discovery Gardens since 1996
In 1994, the Skagit County WSU Extension Master Gardeners had a vision for a garden that would demonstrate best practices for gardening in the Skagit area. After two years of planning, the garden’s first structure of trees and fences was placed in the fall of 1996. Over the following two years, many committed WSU Extension Master Gardeners, along with the help of the community, planted the gardens.

The WSU Master Gardener Program addresses important sociologic and environmental issues by teaching research-based horticulture information. We want people to have important skills and abilities that help mitigate challenges and to understand that everyone has a role to play in creating and sustaining healthy and resilient communities.

Salal Native Plant Garden
The second garden participating in the Tri-Garden Open House is the Salal Native Plant Garden. Bordering the Discovery Garden to the south, the Salal Native Plant Garden is entered by walking through the Discovery Garden following the paths to the south. This labor of love and concern for native plants is manifested in an extensive and charming display garden.

Created twenty-five years ago as a collaborative effort between volunteers of the Salal Chapter of the Washington Native Plant Society and the Washington State University Agriculture Extension Agency at Mount Vernon (WSU), the Native Plant Garden is now a half-acre oasis that holds the seeds for the future of native plants in the lower Skagit Valley. The garden is a terrific resource for homeowners who want to learn how to incorporate more native plants into their landscaping.

Western Washington Fruit Research Foundation (NW Fruit)
The third garden on display is the fruit garden known as the Western Washington Fruit Research Foundation (or NWFruit.org). Here volunteers will answer questions about fruit trees. The 6-acre garden was designed and constructed by volunteers of the foundation and contains large informational signs and handouts based on the research conducted by Washington State University.

During the Open House volunteers will be on hand to explain examples of netting for bird control, a Tatura trellis, and answer questions about the expansive espalier display.

The fruit garden contains a large collection of fruiting plants with many unique varieties, including a collection of 17 variations of Gravenstein apples, a collection of antique apples from all over the world, and unusual fruits such as medlar and blue honeyberry. Located on the west side of the Discovery Garden the fruit garden is open to the public seven days a week from dawn to dusk.

Please join us for the Open House festivities on June 24, 2023 from 10 am – 2 pm. You are welcome to bring a blanket and picnic lunch and enjoy the day with family and friends.

The gardens are open and free to the public throughout the year, 7 days a week from dawn to dusk. Visit the gardens throughout the seasons to view the seasonal changes. Signage in each garden identifies plants and makes for interesting and educational self-guided tours.

 

RESOURCES:

• Discover the Display Gardens website
• Learn about Master Gardener program priorities: https://mastergardener.wsu.edu/priorities/
• Interested in Composting and Vermacomposting? See our recent blog article at: https://www.skagitmg.org/vermicomposting/
• Get started growing your own food: https://www.skagitmg.org/home/resources/food/

ABOUT THE AUTHOR:

Janine Wentworth became a master gardener in 2018. She and Kay Torrance are co-chairs of the Discovery Garden Open House.

 

 

 

 

Questions about home gardening or becoming a master gardener may be directed to: Skagit County WSU Extension Office, 11768 Westar Lane, Suite A, Burlington, WA 98233; by phone: 360-428-4270; or via the website: www.skagit.wsu.edu/mg