Native Habitat:
Moist meadows, wet prairies, marsh edges, streambanks, coastal grasslands, and other seasonally wet habitats of the Pacific Northwest. In the Willamette Valley, it is associated with moist prairie and meadow communities, particularly where soils remain wet in winter and spring but become drier during summer.
Bloom Time:
May – August
Growth Habit & Mature Size:
Perennial clover, typically 1–3 feet tall, spreading by rhizomes and forming colonies. Leaves are divided into three broad leaflets, and rounded to elongated clusters of pink to reddish-purple pea-like flowers are held above the foliage on upright stems.
Light & Soil Requirements:
Full sun to partial shade; prefers moist, fertile soils but tolerates seasonal drying once established. Performs well in loam, clay, and other meadow soils and can tolerate periodic flooding.
Willamette Valley Native Companion Plants:
Camassia leichtlinii
Deschampsia cespitosa
Carex tumulicola
Sidalcea campestris
Helenium bigelovii
Symphyotrichum subspicatum
Urban Garden Function:
An excellent nitrogen-fixing perennial for native wet meadows, rain gardens, bioswales, pollinator gardens, and restoration plantings. Its spreading habit helps knit together meadow plantings and reduce bare soil, while its flowers add midsummer color. As a legume, it forms a symbiotic relationship with nitrogen-fixing bacteria, contributing to nutrient cycling within the plant community.
Wildlife Supported:
The flowers are particularly attractive to bumblebees and other native long-tongued bees, which are well suited to the pea-shaped flowers. Honey bees, solitary bees, butterflies, and flower flies may also visit. The foliage supports herbivorous insects, including clover-feeding caterpillars and beetles, while the seeds are eaten by small birds and other seed-eating wildlife. Its dense growth also provides low cover for spiders, beetles, and other ground-dwelling invertebrates.
Historical Use:
Trifolium wormskioldii was an important traditional food plant for some Indigenous peoples of the Pacific Northwest. The roots and other plant parts were used in different ways depending on community and region. As with other native clovers, its importance today extends beyond its value as a flowering plant to its role in nitrogen cycling, pollinator support, and prairie restoration.
Seed Germination:
Collect mature seed when the flower heads have dried and the small seeds have hardened. Because clover seeds can have a hard seed coat, scarification can improve germination. Lightly rub the seeds with fine sandpaper or nick the seed coat without damaging the embryo. Sow approximately ⅛–¼ inch deep in a well-drained seed-starting mix and keep evenly moist. Germination generally occurs at 60–70°F (16–21°C) within several weeks. A short 30-day cold-moist stratification can be used for seed that has been stored or shows poor germination. Transplant seedlings once they are well established, and provide regular moisture during the first growing season. Once mature, plants can tolerate considerably more summer dryness.
