by Marilee Henry
A main attraction on many springtime hikes in western Washington is spying stately trilliums displaying their exquisite blooms among the forest understory or along shaded trailsides. Also known by the common name "wakerobin", western trillium celebrates the return of robins and the glorious renewal of spring.
Trillium ovatum is the most abundant trillium species in our state and also in western North America, where it ranges from British Columbia to California, and east to Alberta and Montana with pockets in Wyoming and Colorado. It is found in moist varied habitats of open to dense mixed conifer forests to oak woodlands at low to mid elevations in the mountains.
Though once classified as a lily, trilliums are now placed in the hellebore family along with death-camas and beargrass. Though it is not considered highly toxic, it is not recommended that any part of the plant should be eaten as that could result in mild gastric distress.
Western trillium blooms between March and June, and is easily identified by a whorl of 3 large ovate-shaped pointed leaves, 2 to 6 inches in length, attached directly to a single naked stem, topped by a shorter stem bearing 3 narrow sepals and the large 3-petaled flower containing 6 stamens and 3 stigmas. The flowers are a bright white when they first open, but usually turn pink to purple as they age. This change of color occurs when pigments known as anthocyanins, which cause hues from pinks to purples in the corolla, increase as they receive triggers from chemicals produced during aging of the flower and after successful pollination.
Trilliums have complex lives, going through 5 stages to reach maturity. It takes a minimum of 2 winters once planted for a seed to germinate and show its first leaf above ground, and then 3 (under optimal conditions) or more years to bloom. They grow from a thickened rhizome (or bulb) which can spread slowly to produce new plants with 1 to 2 stems per rhizome. The plants go dormant in late summer, with leaves and stems dying back to ground surface. But plants may occasionally remain dormant for a year or more, failing to show during the current growing season but returning for future ones. Mature plants may also randomly revert to a vegetative stage, growing just the leaf whorl without flowering. In wild populations about 20% of the plants may experience either vegetative or dormant states in any given year.
Trilliums have long been highly desirable plants for urban gardens, looking gorgeous nestled among rhododendrons and in the understory of mixed native trees and shrubs, or along the north and east sides of buildings shaded from the hot afternoon sun. Their tolerance for shade, and their hardiness and long life once established (one Oregon trillium was known to have lived to 72 years of age!) make them favorites for western Washington landscaping. They attract important pollinators such as bumblebees, moths, honeybees, beetles, and crab spiders, and host the larvae of moths that are a critical food source for raising baby birds. Trillium seeds each contain a rich packet of fats and proteins called an eliaosome which attract ants and wasps who take the seeds to their nests. The ants and wasps benefit from this important food source while increasing trillium seed dispersal, thus helping to create new populations. The seed pods are also like candy to deer and other small mammals.
Trillium ovatum thrives in shade to partial sun in a moist and organic-rich but well-draining soil that is slightly acidic. If your soil is lacking organic matter, add compost or humus on the surface after planting and mulch well with leaves to help preserve moisture while slowly adding nutrients.
If starting from seed, collect them as soon as the seed pods start to open. Sow at a depth twice the seed diameter. Supplemental watering in early summer for the first few years will encourage growth to maturity in less time. Reduce watering seeds after late summer and all plants after they become dormant. Mature clusters may be carefully dug up in late summer to very early spring before growth starts, dividing the rhizomes such that each has at least one bud, and immediately replanting or repotting each division at the same depth the parent rhizome was found.
Trilliums are under threat from numerous causes. Logging kills the plants as well as the ants that help disperse their seeds, requiring as long as centuries to repopulate a second-growth forest. Fragmentation reduces populations as more and more habitats are destroyed for residences and businesses. Deer and elk may overgraze them as their food sources are diminished. Harvesting by humans for landscaping or medical uses is another problem. And last but not least, drought caused by climate change is reducing their available habitats.
Because they take so many years to establish from seed, and considering all the above threats, trilliums should NEVER BE COLLECTED FROM THE WILD, unless it is certain the plants are otherwise doomed, as in the case of housing developments.
Attempted salvaging of the fragile bulbs can result in their death and/or that of those growing nearby. Also remember that picking a wildflower results not only in its quick demise, but robs the environment of future generations that might have grown from seeds that will now never develop. In the specific case of trillium, picking the flower will reduce photosynthesis (by the sepals and/or leaves) needed to store energy in the rhizome for the next season's growth.
There is such demand for this species that many native plant nurseries are growing it from seed under optimal conditions that produce beautiful mature plants in 3 to 4 years, making them available at most native plant sales.
Admire this stunning species in the wild with eyes or camera but do not touch. Help preserve the species by growing Trillium ovatum in your own garden or in a pot!
Always remember, "You are nature's best hope!" - Doug Tallamy, author of "Nature's Best Hope" and "Bringing Nature Home".
Marilee Henry
Kirkland Community Wildlife Habitat Team Member, Washington Native Plant Society (WNPS) Native Plant Steward, Green Kirkland Steward, Finn Hill Neighborhood Alliance Contributor
Pacific Rim Institute, Coupville, Wa. Prairie Days Native Plant Sale
May 2, 3, & 4 details here
Snohomish County Master Gardener Plant Sale
May 10, 2025, 9am - 2pm, Monroe Fairgrounds
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MsK Nursery at Kruckeberg Botanic Garden, Shoreline
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May 9, 10, & 11, 2025, 10am - 5pm
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Lake Forest Park Garden Club Plant Sale
May 17, 2025, 9am - 1pm
Lake Forest Park Elementary School
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