Who’s Who? Noxious Weeds and their Look-Alikes
Perennial pepperweed can be hard to find when growing among cattails—and look-alikes make the job even harder.
Weed Specialist Mary Fee paces through the wetlands at Dumas Bay Wildlife Sanctuary, scanning the cattails around her. Every few dozen feet she stops to inspect a smaller plant growing among them. She’s looking for perennial pepperweed (Lepidium latifolium), a Class B Noxious Weed in King County. The plant is hard enough to find among the dense wetland foliage, but that’s not Mary’s only problem: like many other noxious weeds, perennial pepperweed has a number of deceptive look-alikes. These plants can make identifying noxious weeds a tough job!
Perennial pepperweed is a 2- to 6-foot-tall herbaceous perennial with many stems that grow from a woody root crown. You’ll often find it growing in salty areas, such as beaches, marshes, and wetlands, but it can adapt to a wide range of areas. Its leaves are waxy, serrated or entire, have distinct whitish mid-veins, and appear alternate on the stems. Basal leaves are lance-shaped and up to 12 inches long with stalks nearly the same length, while stem leaves are smaller with shorter stalks. Pepperweed grows from a rosette and blooms June-September, when dense rounded clusters of small white flowers appear near branch ends. The plant spreads mainly through root fragments, though it also produces seeds in small egg-shaped pods.
Perennial pepperweed blooms June-September, when dense rounded clusters of small white flowers appear near branch ends.
At Dumas Bay, we find two plants that might be confused with perennial pepperweed. The first is Puget Sound gumweed (Grindelia integrifolia) which, despite its name, is native to the Pacific Northwest. It’s easy to mix up this plant with pepperweed. Like pepperweed, gumweed is a usually multi-stemmed perennial with a woody root crown and serrated or entire leaves growing alternate on its stems. It also occurs in many of the same habitats: salt marshes, beaches, and other shoreline areas. Luckily, when the two plants are in bloom they’re easy to tell apart: gumweed has yellow composite flowers with bracts covered in a white, sticky “gum” (hence the name). If you find a plant that isn’t blooming, check its leaves: unlike pepperweed, gumweed’s stem leaves lack stalks. At ½ to 2 ½ feet tall, the whole plant is also usually shorter than pepperweed.
Puget Sound gumweed has yellow composite flowers with bracts covered in a white, sticky “gum”—very different from perennial pepperweed’s flowers. Photo courtesy of Bureau of Land Management Oregon and Washington / CC BY 2.0.
You might also confuse perennial pepperweed with bittersweet nightshade (Solanum dulcamara), a widespread invasive plant (and “Weed of Concern”) in King County. While bittersweet nightshade often appears as a vine, you can also find it growing as a standalone shrub. Unlike the two above plants, nightshade’s leaves tend to have lobes near their bases. The roots also grow mostly horizontally, in contrast to the deep root systems of pepperweed and gumweed. And again, this plant’s flowers clearly distinguish it from the above-mentioned look-alikes: bittersweet nightshade has small star-shaped purple flowers with central yellow cones that appear between mid-May and September. It also produces numerous bright red berries that are somewhat toxic to people and animals (though not as dangerous as those of deadly nightshade (Atropa belladonna)).
Unlike perennial pepperweed and Puget Sound gumweed, bittersweet nightshade’s leaves often have lobes at their bases. Flowers are star-shaped and purple with yellow cones.
Later that day, Mary and I visit a tansy ragwort (Senecio jacobaea) infestation just southeast of Saghalie Park in Federal Way. Scattered on a slope we find small plants sprouting through a layer of wood chips. They look just like tansy ragwort—only something’s not quite right.
Tansy ragwort is a generally biennial plant that spends its first year as a basal rosette with ruffled leaves. In the second year, the plant reaches up to 6 feet tall. Its ruffly-looking leaves have deeply cut, blunt-toothed lobes, and are dark green above and whitish-green below. Mature plants flower between June and October, producing clusters of bright yellow daisy-like flowers—usually with 13 petals—at the ends of its stems. One plant can produce up to 150,000 wind-dispersed seeds, which remain viable in soil for up to 15 years.
Tansy ragwort is an especially dangerous plant because it often grows in pastures and is toxic to people and animals. While livestock tend to avoid live tansy ragwort plants because of their bitter taste, when plants are cut and dried with hay they lose their bitterness—but not their toxicity.
Tansy ragwort produces clusters of bright yellow daisy-like flowers—usually with 13 petals—at the ends of its stems.
The first plant we find is common groundsel (Senecio vulgaris). Like tansy ragwort, this winter annual starts life as a basal rosette and mature plants have deeply lobed leaves. However, common groundsel only reaches 5-10 inches tall at maturity, and its yellow flower heads lack rays.
At 5-10 inches tall, common groundsel is much smaller than tansy ragwort. Photo courtesy of Matt Lavin / CC BY 2.0.
Common groundsel’s deeply lobed leaves aren’t as ruffled-looking as those of tansy ragwort. Photo courtesy of Andrew Zharkikh / CC BY 2.0.
We also find woodland groundsel (Senecio sylvaticus), which looks even more similar to tansy ragwort. Like common groundsel, woodland groundsel is an annual, but mature plants reach up to 2½ feet tall. Its yellow flower heads have ray flowers, as do those of tansy ragwort, but woodland groundsel’s ray flowers are tiny—less than 2 mm long—while tansy ragwort’s are 4-10 mm long. When not in flower, you might also be able to distinguish the two groundsels from tansy ragwort by their leaves: tansy ragwort’s ruffled leaves have more of a three-dimensional appearance, while the groundsels’ deeply lobed leaves are flatter.
Though taller than common groundsel, woodland groundsel is on average shorter than tansy ragwort. Photo courtesy of Forest and Kim Starr / CC BY 2.0.
Woodland groundsel’s leaves are deeply lobed but not as ruffled-looking as those of tansy ragwort. Photo courtesy of Forest and Kim Starr / CC BY 2.0.
Woodland groundsel’s ray flowers are less than 2 mm long, while tansy ragwort’s are 4-10 mm. Photo courtesy of Forest and Kim Starr / CC BY 2.0.
Tansy ragwort is also easily confused with common tansy (Tanacetum vulgare), a Class C noxious weed in King County. This perennial grows 2-6 feet tall and produces bright yellow flowers at about the same time as tansy ragwort does. But up close, they’re easier to tell apart. Common tansy’s flowers look like buttons and lack ray flowers. Its alternate leaves also appear much more fern-like, in contrast to tansy ragwort’s deeply lobed, ruffled leaves.
From a distance, common tansy looks similar to tansy ragwort. Photo courtesy of Matt Lavin / CC BY 2.0.
Common tansy leaves look fern-like, in contrast to the deeply-lobed shaped of tansy ragwort’s leaves.
A final tansy ragwort look-alike is common St. Johnswort (Hypericum perforatum), another Class C noxious weed. Common St. Johnswort is an herbaceous perennial that usually reaches 1-3 feet tall. Its yellow, star-shaped flowers have five petals, and its oval leaves have distinct black or transparent dots.
From a distance, Common St. Johnswort looks similar to tansy ragwort, though it usually reaches only 3 feet tall.
Throughout the day, Mary and I also visit a series of goatsrue (Galega officinalis) infestations. Goatsrue is a 2- to 6-foot-tall herbaceous perennial with multiple hollow, upright stems growing from a deep taproot. It has alternate leaves with 13-21 leaflets. From June to October, purple to white pea-like flowers appear in clusters at stem ends.
Goatsrue has alternate leaves with 13-21 leaflets. From June to October, purple to white pea-like flowers appear in clusters at stem ends. Note the absence of tendrils at leaf end. Goatsrue has white to purple pea-like flowers.
Goatsrue only occurs in a few places in King County, but it has multiple look-alikes that are more common. For instance, you might confuse goatsrue with one of the vetch species growing in our area. However, goatsrue tends to grow much more upright than the clambering form of vetch, and goatsrue lacks the tendrils at leaf tips shared by vetch species.
Tufted vetch (Vicia cracca). Note the tendrils at leaf ends. Photo courtesy of Patrice Wuine / CC BY 2.0.
American vetch (Vicia americana). Note the tendril at leaf end. Photo courtesy of Julie dewilde / CC BY 2.0.
Goatsrue also looks very similar to wild licorice (Glycyrrhiza lepidota), a native perennial. Wild licorice’s leaves are somewhat similar to those of goatsrue, as are its cream-colored flowers. However, wild licorice usually reaches only 3 feet tall and has solid stems, in contrast to the hollow stems of goatsrue. Wild licorice also has seed pods with hooked bristles, while goatsrue has smooth seed pods.
The pinnately compound leaves are somewhat sticky because of the punctate glands that occur throughout each of the individual leaflets.
Glycyrrhiza lepidota is typical of many native (and exotic) legumes and grasses in thriving in the human habitat but only where physical disturbances maintain a minimum of other plant species and where soil moisture is often present. This setting represents perfect cheatgrass (Bromus tectorum) habitat in northwestern New Mexico and elsewhere.
Not sure if you’ve found a noxious weed? Don’t worry! Send us a photo by emailing us at [email protected] or mailing it to: King County Noxious Weed Control Program, 201 S Jackson St, Suite 600, Seattle WA 98104. And feel free to call us at 206-477-WEED (206-477-9333)!
Windcliff Plants is a small endeavor on our property that has the luxury of propagating only those plants that we feel deserve greater recognition in gardens of North America; you will not find filler or bread and butter crops in this listing. But for few exceptions, the entirety of our inventory is part of my own collection work with their provenance and collection numbers in the plant description or provided upon request.
Sorry; we do NOT do mail-order. These plants are available to order online and pickup at Windcliff. With some exceptions, a wholesale quantity discount is available on limited items for legitimate businesses.
You can make an appointment to visit our garden and nursery. We do not produce in large quantities, so please check regarding availability before your visit. See events for other plant shopping opportunities.
(Plant list updated March 25, 2022)
Shop Windcliff Plants
In 2022, we are scheduling appointments to shop at Windcliff (Indianola, WA). Review details for ordering our plants and Windcliff garden visits. Heronswood, owned by the Port Gamble S’Klallam Tribe, offers a limited selection of Windcliff Plants and other plants for sale. Check open hours at the Heronswood website. Consider visiting Windcliff and Heronswood on the same day, and have a North Kitsap plant adventure!
May 2020 Video Garden Tours
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April 2020 Video Garden Tours
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March 2020 Video Garden Tours
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Real Gardens Grow Natives
Pacific Northwest Native Plant Profile: Pine (Pinus species)
Well over one hundred species of pine help support our planet, which makes the genus Pinus the largest within the conifer phylum known as Pinophyta, the woody cone-bearing plants. Found across the Northern Hemisphere, Pinus is of ancient origin, having appeared around 180 million years ago. In addition to the rich wildlife habitat, beauty, shade, fragrance, rain interception and carbon sequestration they provide, the majority of pines are drought tolerant, fire resistant and most can be extremely long-lived, with some species surviving 1,000+ years when undisturbed.
How they grow
Evergreen and resinous, pines generally grow 50–150 ft tall, although some, like ponderosa pine, can grow over 200 feet (one in southern Oregon’s Rogue River-Siskiyou National Forest towers to more than 268 feet tall!).
On adult pine trees, needle-like leaves are green and bundled in clusters called fascicles, unlike other conifers. Each fascicle can have one to seven needles, depending on the species, and assist in identification. In the Pacific Northwest west of the Cascades, there are five native pine species, a few of which can also be found at fairly high elevations east of the Cascades summit. They have either two, three, or five needles per fascicle, which stay on the plant for anywhere from two to forty years, again depending on the species.
Seed cones (female) are hard and woody, with tough scales that serve to protect the developing seeds until dispersal time comes. In some species, maturity of the cone causes scales to open and free the winged seeds. In others, scales need to be broken or pecked open by a hungry animal in order for the seeds to be released. And then there are the species that have scales sealed shut with resin: Known as “serotinous” cones, they need a trigger to release their seeds. Although serotiny can be caused in some plants by excessively moist or dry conditions, high solar heat, or death of a branch or the plant, most pines that are native to regions where wildfire naturally occurs depend on the high temperatures from periodic fire to soften the resin and expose the seeds. Fire has been a part of various natural ecosystems for millennia; having a canopy full of seeds ready to go following a fire ensures dispersal for a new generation without competition. But it can take decades for that to happen and on many sites currently, such fire regimes no longer exist. When natural fire is suppressed, species that need fire to regenerate will slowly die without ever releasing their seeds, and species dependent on those pines are consequently affected.
Pines do best in open areas and are not shade-tolerant. Generally, they don’t need rich soil and do best if it drains fairly quickly. Some can survive in harsh environments such as cold, exposed ridges at high elevations or latitudes, or even the wet and windy Pacific coast.
Pines are one of the most valuable food plants for wildlife in the Pacific Northwest, particularly for small mammals like chipmunks and squirrels, as well as birds such as grosbeaks, jays, chickadees, and nuthatches who forage on the highly nutritious seeds and help distribute them. Larger birds, including woodpeckers, also use pine trees as food sources, particularly dead and dying pines. Pine needles may be eaten by some Lepidoptera (butterfly and moth) species (such as the larvae of western pine elfin that use lodgepole and ponderosa pine for food), as well as by pine sawfly, deer, and mountain goats; needles are also used in nest building. Large pines provide excellent roost and nest sites, while smaller pines offer crucial cover for many animals. Fallen needles may serve as bedding for larger mammals such as deer.
Native pines west of the Cascades
Below is info on the five native pine species that occur in the PNW west of the Cascades, plus one honorable mention; they are noted according to the number of needles per fascicle. If you want to identify a particular tree, count the needles per fascicle, evaluate the appearance of the cones, and check the natural range.
Fast-growing Pinus contorta evolved into four varieties, each of which adapted to its geography. Despite their large ecological and morphological variability, all varieties of P. contorta have two stiff, one to three-inch long needles per fascicle, which are often twisted and are mostly found toward the ends of twigs. The seed cones are small (typically one to three inches long), hard, prickled toward the top of the cone, and found near branch tips. The varieties are inter fertile in areas where their ranges overlap.
Three varieties are found in the PNW. It was shore pine (a.k.a. beach pine or twisted pine), Pinus contorta var. contorta, that led David Douglas to offer the species’ epithet contorta when he first laid eyes on one in 1826: Reportedly, he found some relatively short trees growing in contorted and gnarly outlines near the mouth of the Columbia River on wind-swept, rocky sites with the added insult of oceanic salt spray. Bark is thick, deeply grooved, and a deep red-brown in color. Small brown cones are often asymmetrical and release seeds at maturity. Adapted to poor and rocky soils, shore pine’s range includes the San Juan islands, the outer coasts of British Columbia, Oregon, Washington and northern California, bogs of Alaska and Washington, and only occasionally the Puget-Willamette Trough. On more sheltered sites, this coastal species will grow taller and more erect (up to about 50 feet tall), and slightly resembles the appearance of Pinus contorta var. latifolia (lodgepole pine), which naturally occurs further inland, mainly in the Washington Cascades east of the Puget Trough and at higher elevations (up to 11,500 feet).
Lodgepole pine grows taller (up to ~100 feet) and more slender (especially when growing close together) with thin bark and a narrow crown. Adapted to stand-destroying fire, it is one of the first trees to come back after a natural periodic fire; its cones, which vary in shape and may be solitary or paired, are considered fire-dependent. However, this cone characteristic varies with tree age and local fire history, with older trees and those growing in areas with frequent fires able to produce serotinous cones. Remarkably, some lodgepole pine trees are even more variable, having both serotinous and nonserotinous cones, which may enable future trees to adapt to change.
Pinus contorta var. murrayana, Sierra-Cascade lodgepole pine, grows in the eastern Cascades of southern Washington, Oregon and the mountains of California. Its cones usually open on the tree when mature, before a fire. Both lodgepole pines will grow in situations that other conifers cannot tolerate.
Another tall, handsome pine is Pinus ponderosa, or ponderosa pine (aka western yellow pine), a fairly fast-growing tree to 100 feet by 25 feet in cultivation, larger in natural areas. With bundles of three long, pointed bright green needles that fall off after several years, ponderosa pine has a straight, robust trunk and a wide, open, cylindrical crown when mature. Bark is furrowed and dark on young trees; on older trees the thick, fire-resistant bark typically turns a golden brown or cinnamon color, flakes off into scaly plates separated by deep fissures, and has a vanilla scent in heat. Tan to reddish-brown, conical or egg-shaped female cones have stiff prickles that curve outward. The root system spreads widely and has a deep taproot. Although best grown in full sun with well drained, deep, somewhat moist soil when young, ponderosa pine is reportedly adaptable to a variety of elevations, soil and humidity, and is drought tolerant when established. Damage may occur due to late frosts.
Ponderosa pine is subdivided into five subspecies; P. ponderosa subsp. ponderosa is most commonly found in cold, dry environments east of the Cascade summit, throughout the Rocky Mountains and southward. Pinus ponderosa subsp. Benthamiana (aka Pacific ponderosa) is endemic to the Willamette Valley (where it is sometimes called Willamette Valley pine or Pinus ponderosa var. willamettensis), as well as the mountains of southwestern Oregon, parts of California and a few sites in western Washington. Genetically different from ponderosa subspecies in other ecoregions, it usually has longer needles (up to nine inches) and is suited to higher rainfall in valley bottoms, as well as drier slopes. Prior to 1850, it thrived in oak savanna, riparian forest and upland prairie dispersed among other species (particularly Oregon white oak, Quercus garryana). Logged extensively by settlers as they cleared the land for lumber, agriculture and other development, until recently the only remaining native stock in the Willamette Valley survived in small scattered stands. Wildlife who needed the trees for food and nesting habitat suffered from the loss, including the rapidly dwindling Lewis’s woodpecker (now extirpated; there have been no breeding records in the Puget Lowlands since 1980; the last known nest in the Willamette Valley was near Scapoose in 1970; they have not been seen in the Rogue and Umpqua Valleys since the early 1990s). While this pine does best in full sun and moist but well-draining soil, it also tolerates somewhat dry conditions and lean soils. Choose associate species from Oregon white oak (Quercus garryana) ecosystems in this post.
Another three -needled pine that possesses similarities to ponderosa pine is Jeffrey pine, Pinus jeffreyi, named by Scottish botanist John Jeffrey. A major difference is its range: In the PNW it occurs only in southwestern Oregon at 4800 to 9600 feet in elevation, often in windswept outcroppings or on serpentine and other nutrient-poor soils where it grows slowly but outcompetes other trees. In addition, its needles are a duller bluish-gray and thicker than ponderosa pine’s, and they are typically held longer (five to eight years). Cones become much larger (up to 12 inches long), with prickles that curve inward. Older bark tends to be darker and more narrowly grooved than that of ponderosa’s.
Pinus attenuata (knobcone pine) also has fascicles of three yellow-green needles, which are typically three to seven inches in length and twisted. Buff colored, three to six inch, serotinous cones — that let go of seeds only after fire melts the resin — have knobby bumps on one side, and grow in bristly, dense clusters. Bark is dark with loose, scaly plates on this very long-lived, relatively small (30 to 50 foot) tree with a conical crown; it may be shrubby on poor sites. In the PNW west of the Cascades it’s found mainly in southwestern Oregon on rocky slopes at high elevations that are prone to fire (often on serpentine soils), as well as further south into parts of California and Baja.
Pinus lambertiana (sugar pine) is a very large tree (120 to 200 feet tall) that has fascicles of five pointed needles that are two to four inches in length and striped with white on all three sides. Woody cones are straight and grow very large (up to 19 inches), with straight, thick scales. Bark is reddish-brown to purplish and furrowed; on young trees it’s broken into narrow plates and on mature trees broken into long plates. It’s found at mid to high elevations in the mountains of southern Oregon (from Linn County, southward), as well as southern California, the Sierra Nevada range and northern Baja. David Douglas named the species lambertiana in honor of the English botanist Aylmer Bourke Lambert in 1826.
You may be familiar with Pinus monticola, Western white pine, since it is fairly common and easy to grow (despite its susceptibility to white pine blister-rust). A large, symmetrical tree (to 130 feet but smaller in cultivation), it also has fascicles of five needles, but white pine’s thin bluish-green needles have (surprise!) white lines on two sides of each 3-sided needle. Slender, curved woody cones are four to ten inches long, with scales that are thin and may be curved but without prickles. Bark is gray, thin, and broken into small rectangular or hexagonal scaly plates on mature trees. Range includes southern British Columbia, Washington, Oregon, and California’s Sierra Nevada, from sea level to about 2500 feet in elevation in moist valleys and open slopes.
The very slow-growing, often shrub-like or gnarled Pinus albicaulis (whitebark pine) also has short needles in bundles of five , thin grayish bark, and small roundish cones without prickles that remain closed on the tree at any age. Since it naturally occurs only at high elevations (near timberline) in southern B.C, the Olympics, the Cascades, east-central California and the Rocky Mountains, you won’t be tempted to grow it in your low elevation yard, but I’ll mention it as it certainly deserves our attention and concern.
Data from USFS Forest Inventory and Analysis surveys report that “as of 2016, 51% of all standing whitebark pine trees in the US were dead” and over half of that amount occurred approximately within the last two decades. Due to severe population decline, the USFWS determined that it “warrants protection under the Endangered Species Act (ESA), but … adding the species to the Federal List of Endangered and Threatened Wildlife and Plants is precluded by the need to address other listing actions of a higher priority.” The severe decline is attributed to multiple stressors, especially white pine blister rust (introduced into western North America through the horticulture trade in 1910), but also outbreaks of mountain pine beetle (made worse by a warming climate), fire suppression and catastrophic fire, poor management, and, of course, climate chaos.
Whitebark pine is very long-lived, with some surviving 1,000 years. Considered a keystone species, it regulates runoff by slowing down snowmelt, controls soil erosion due to its ability to grow quickly after disturbances such as fires, and provides a rich source of food for birds like Clark’s nutcracker and mammals such as grizzly bears. It depends almost exclusively on Clark’s nutcracker for seed dispersal, but there needs to be sufficient density and seed abundance to attract the birds.
Try pines at home
If you want to add pines to your landscape, remember that it’s best to grow native trees and other plants that truly belong in your neck o’ the woods. Obtain plants propagated from source material that originated as close as possible to your site and with similar habitat features. Using such “local genotypes” helps ensure that you get plants that are well adapted to your area and preserves the genetic diversity that helps plants and animals adapt to changing conditions. Ask growers and nurseries about their sources if you’re unsure.
Provide good drainage and enough sun and space (both above and below ground) for these beauties. Whenever possible, grow them with their natural associate species, which have similar needs, to recreate a native plant community that is able to impart the most benefits to the ecosystem and result in more habitat for wildlife. And if you have the space, plant a grove!
Pacific Northwest Native Plant Profile: Erysimum capitatum (Western wallflower)
Unlike the proverbial human wallflower, the Pacific Northwest’s native wallflower plant (Erysimum capitatum) isn’t shy or unassuming. Instead, it is bright, showy, sweetly fragrant, and attractive to pollinators like butterflies and bees. Although it didn’t make it into my book, it is definitely worthy of praise and recommendation.
The genus Erysimum, a member of the cabbage (Brassicacaeae) family, contains about 150 species found throughout much of the northern hemisphere. Growth habits may be annual, short-lived perennial, or woody perennial. Carl Linnaeus named the genus after the Greek word eryomai, which means “to help or save” in reference to the medicinal qualities of several species. European folk medicine practitioners used poultices of wallflower for bronchial congestion, while Native Americans made tea with the dried leaves or seeds of wallflower to relieve stomach cramps.
In the U.S., western wallflower (aka prairie rocket, Douglas wallflower and sand dune wallflower) occurs in many different habitats throughout the west, including parts of Washington, Oregon, California, and southern British Columbia (usually below 4,000 feet). In Washington, Erysimum capitatum var. capitatum is generally found east of the Cascades and in the Olympic Range; in Oregon it is generally found east of the Cascades as well as westward through the Columbia River Gorge and into the Willamette Valley, and in the Siskiyous. Several other varieties or subspecies are endemic to California; at least one (E. c. var. angustatum) is listed as endangered due to development, mining, agriculture, and invasive plants.
How it grows
Although western wallflower is technically a perennial plant, it’s often considered a biennial due to its short lifespan (rarely does it live past its second year). Like other short-lived perennials, it has a strong tendency to self-sow and is quite easy to grow from seed in pots or outdoor beds (but seeds reportedly have a short shelf life, so use them within a year).
Although wallflowers’ growth form and appearance vary (depending on location, light, soil, and moisture), here’s a general description: Deep green leaves — numerous, usually hairy, long and narrow — grow in a basal rosette, as well as along erect stems. Clusters of four-petalled flowers are bright yellow to deep orange and appear at stem tips in a raceme. Bloom time is late April to July (depending on conditions and location); the resulting fruit is a one to four inch, upright, slender, flat seed pod called a ‘silique‘. In bloom, plants may reach one to three feet tall, with a spread of one-half to two feet.
Western wallflower plants are important food sources for wildlife, including the caterpillars of some lepidoptera (butterfly and moth) species, including the Sara’s Orangetip butterfly (Anthrocharis sara). Nocturnal moths and other butterflies, such as Painted Lady (Vanessa cardui), Anise swallowtail (Papilio zelicaon), Pale Tiger Swallowtail (Papilio eurymedon), and Persius Duskywing (Erynnis persius) are a few that may use the plant for nectar, as do some native bee and ant species. Mature seeds turn a deep orange and are eaten by — you guessed it — insects and birds that eat seeds.
Try it at home
Easy to grow and with a lengthy bloom period, western wallflower will brighten up any spot in full sun to light shade and looks particularly dazzling with a dark backdrop. Tolerant of drought since it typically occurs in dry, rocky, clayey, or sandy locations, it needs well-drained soil to thrive, but will take artificial irrigation if drainage is adequate; additional moisture during dry months may even prolong its bloom time. Growing plants en masse, in swathes or drifts, will provide the most visual impact and support for wild ones, but they also look lovely interspersed with plants such as penstemon. Space plants about one to two 2 feet apart.
As always, buy plants propagated from source material that originated as close as possible to your site. Using such “local genotypes” helps ensure that you get plants that are well adapted to your area and preserves the genetic diversity that helps plants (and animals) adapt to changing conditions. Ask growers and nurseries about their sources if you’re unsure.
Pacific Northwest Native Plant Profile: Red-flowering Currant (Ribes sanguineum)
Although red-flowering currant (Ribes sanguineum) is a deciduous shrub, it offers year round appeal and habitat, making it a favorite among Pacific Northwest gardeners and wildlife, alike. Not one December goes by that I don’t marvel at its ability to hold onto many of its seasonally colorful leaves until the solstice or beyond, and this year was no exception. Just a short while later—following barely two months of downtime in the new year—strikingly gorgeous flower clusters burst forth prolifically at the same time that fresh leaves emerge. No wonder another of its common names is “winter currant.” Fast forward a few more months, and dark dusty-blue berries, a favorite of many bird species, will adorn this multi-stemmed shrub.
The sole genus in the Grossulariaceae family, Ribes means ‘currant’ in medieval Latin. One of about 30 currant and gooseberry species in the Northwest, sanguineum refers to the reddish color of the flowers. It’s one of those native plants that had to be chaperoned by Scottish botanist David Douglas to Britain—where it was introduced into cultivation in the 1820s—before it acquired a return transatlantic ticket to popularity with gardeners on its home turf. Not too small or huge, it can usually find a home in places that offer well-drained soil and at least a quarter day of sun.
How it grows
Red-flowering currant naturally occurs at the edge of forests as well as open, rocky slopes and disturbed sites, at low to middle elevations from southwest British Columbia into Washington and Oregon between the Pacific coast and the Cascades, and as far south as central California.
Pendulous flower clusters, which consist of numerous lightly fragrant, pink to reddish tubular flowers, bloom in profusion along this shrub’s many stems. They offer nectar and pollen at a time when early-emerging pollinators—such as queen bumble bees who must secure a nest and provide for offspring all by themselves—have little else to eat. The early blossoms are also attractive to birds, especially hummingbirds, but also bushtits, making this species a hub of wildlife activity for well over a month. Later on, when berries ripen as summer wanes, birds such as American robins and cedar waxwings (pictured, below) feast; we can also eat them but they are rather tasteless. The small, lobed leaves may provide food for zephyr (Polygonia gracilis zephyrus), Ceanothus silkmoth (Hyalophora euryalus), and other butterfly and moth larvae, which in turn supply food for insectivorous birds.
Try it at home
Red-flowering currant prefers sun to part sun, and well-drained soil. While tolerant of clay soils, it doesn’t do well on poorly drained sites. Useful for erosion control on slopes, it may eventually form a thicket, which is helpful for wildlife that needs cover.
Mature size varies from around six to ten feet tall; width is typically similar, so do allow it enough space. A fast grower, it may reach four or five feet in just a few years and even produce blossoms as well. If you’re looking to use this shrub in a border, space them five to ten feet apart (on the low end if you want some density and overlap). Although this shrub is quite drought tolerant when established (after two to three years), water it deeply but infrequently in the hot summer months thereafter, especially if your site receives a lot of sun or reflected heat for buildings or fencing, or drainage is quick.
Propagation is best achieved via self-sown seed, which are easily dispersed by birds or fall to the ground below. If you want to DIY, collect seeds as soon as fruit is ripe in mid to late summer, dry them in a shaded place, then sow in autumn (outdoors to allow for stratification). Seed reportedly has a long shelf life if stored in a cool/dry/dark place.
Grab a partner
Since red-flowering currant grows in a fairly wide range of habitats, there are a number of plants with which it interacts in intact ecosystems. For best ecological and gardening results, choose associated native plants that live in communities that currently grow or likely would have grown in your immediate area. In the Pacific Northwest, some of the plants that red-flowering closely associates with include Douglas-fir, bigleaf maple, madrone, bitter cherry, oceanspray, vine maple, elderberry, mock orange, serviceberry, manzanita, salal, sword fern, kinnikinnick, and others.
Buy plants propagated from source material that originated as close as possible to your site. Using such “local genotypes” helps ensure that you get plants that are well adapted to your area and preserves the genetic diversity that helps plants (and animals) adapt to changing conditions. Ask growers and nurseries about their sources if you’re unsure.
Although many cultivars—with a range of flower color—have been developed, it’s best to choose true species or varieties found in nature. A related species for very moist places is wild gooseberry (Ribes divaricatum), which has edible fruit.
Pacific Northwest Native Plant Profile: Oregon grape (Mahonia species)
Oregon grape plants are colorful western shrubs with year round appeal and chances are there’s a species that will fit into your Pacific Northwest landscape. Named after Bernard McMahon, an Irish-born American nurseryman, the genus Mahonia is a member of the barberry family (Berberidaceae). But you may also see Oregon grape classified as Berberis, indicative of the extensive debate among botanists on how to classify this species. Although included in the large genus Berberis (an alteration of the Medieval Latin barberis, or barberry, from Arabic barbārīs), Oregon grape is still known as Mahonia in most commercial horticulture, so either is correct (at least as far as I’m concerned!).
Oregon grape plants are extremely beneficial and attractive to wildlife. Flowers provide for pollinators like bees, moths, butterflies, and hummingbirds, while the fruits, which may remain on the plant into winter, are favorites among birds such as towhees, robins, and waxwings, as well as mammals. Some butterfly and moth species rely on Oregon grape plants to host their larvae, including the brown elfin butterfly. Year round cover may support arthropods, birds, reptiles, amphibians and small mammals.
Cedar waxwings feed on Cascade Oregon grape (M. nervosa). ©Eileen M Stark
You can’t go wrong with tall Oregon grape (Mahonia aquifolium) for an evergreen, erosion-controlling, woody-stemmed, slightly prickly screen, barrier or woodland border, as part of an unpruned hedgerow, or as an accent plant (pictured top and right). Aquifolium means “water leaf,” likely named after the lustrous, wet-looking surface of the plant’s leathery leaves that Lewis and Clark first noticed near the Columbia River. Introduced to Britain in the 1820s as an expensive ornamental, its holly-like, pinnately compound leaves begin a bronzy coppery color, then mature to a deep green, with orange, red, or purple highlights in very sunny or cold conditions. Dense clusters of showy golden-yellow, lightly fragrant flowers appear in early to late spring. Ripening in late summer, the dusty-blue, round to oblong berries are slightly reminiscent of grapes, hence the name. Although they are tart and have large seeds, they are suitable for jams and jellies (with beaucoup sweetener) and have traditional medicinal properties, as do the roots.
Tall Oregon grape’s range includes most of western Washington and Oregon, parts of Idaho and much of California, as well as northeastern Washington and southern B.C. It can handle nearly full sun to shade, but being a woodland species often found growing in somewhat open forests, it prefers some shade (although very deep shade will result in fewer flowers and fruit). Though it does best in slightly moist, acidic, well-drained soil, it’s an undemanding plant that can handle many soil types and drought when established. However, it is intolerant of poorly drained soils and high water tables. Since it will gradually spread into a thicket via tough rhizomes, place it away from pathways and allow it to eventually spread into a wildlife protective clump. If you don’t plan for its growth or it somehow gets out of hand, roots may be occasionally pruned and stems may be cut (as seldom as possible) nearly to the base for renewal. Arching stems typically reach four to eight feet in height, typically on the lower end in garden situations.
Try growing it with trees and shrubs such as Douglas-fir, western hemlock, ponderosa pine, vine maple, Indian plum, oceanspray, serviceberry, salal, and smaller companions like sword fern, western columbine, fleabanes, delphinium, and others.
Cascade (or long leaved) Oregon grape (Mahonia nervosa) is another handsome plant, but this one grows only up to about two feet tall, often lacks shiny leaves, and very slowly spreads into a lovely, evergreen, soil-stabilizing ground cover over many years. Nervosa means “having distinct veins or nerves” and refers to the leaf venation. Showy, fragrant, erect, pale to bright yellow flowering stalks, which put on their show in early to mid spring, are trailed by the familiar deep blue berries in late summer to fall.
This species naturally occurs in moist to dry forests, at low to mid elevations mainly west of the Cascades including Vancouver Island, often with oceanspray, Indian plum, vine maple, sword fern, salal, and oxalis, but it’s also an associate of the drier Oregon white oak and madrone habitats. It prefers shade to part shade in moist, acidic soil, but can handle drought in cool areas when established. It’s a nice substitute for invasive English ivy.
Low (or creeping) Oregon grape (Mahonia repens) is an evergreen ground cover that grows one to two feet tall and four to six feet wide. It has a large range in the west; in Washington and Oregon it is mainly found east of the Cascades growing in conifer forests, so it does well in dry, shady conditions but can take some sun. Its leaves (pictured below) may be glossy or dull, tend to be rounder and—though toothed—feel less prickly than tall Oregon grape. In nature, where its range sometimes overlaps with tall Oregon grape (and in garden situations where we often place plants that don’t belong together), it may hybridize with its cousin and produce plants that are a bit taller than the true species.
All Oregon grape species are best grown from seed (without drying them), with at least three months of cold stratification outdoors (wet pre-chilled seed may also be planted in spring). Seed germination is reportedly erratic and unpredictable. If you have established plants you may find their progeny beneath them or elsewhere, as seeds are dispersed by birds and mammals; anything but very small transplants may not survive. Cuttings may also be tried in late fall.
As always, buy plants propagated from source material that originated as close as possible to your site. Using such “local genotypes” helps ensure that you get plants that are well adapted to your area and that genetic diversity—which helps plants (and animals) adapt to changing conditions—is preserved. Ask growers and nurseries about their sources if you’re unsure.
Do you have Oregon grape but aren’t sure which species you have? This page has a handy leaf comparison (see photo on lower right).