Hosackia pinnata, Bog Bird’s Foot Trefoil seed
Annual clover, 12–28". Fixes nitrogen, adds spring blooms, and enhances soil quality. An upright habit makes it best for open beds. Covers 1 sq ft.
From Northwest Meadowscapes.
An ornate perennial legume, bog bird’s foot trefoil, occurs from British Columbia to California, where it is closely associated with cool and damp sites: low meadows, seasonally wet bogs, stream edges, and shallow soils with sub-surface seeps or springs. That said, with rich soils and a little encouragement this handsome little plant can also adapt well to many upland sites.
From its sprawling form (growing up to about a foot in height), bog bird’s foot trefoil produces showy inflorescences of yellow and white flowers, arranged in complex pinwheels. Bumble bees are avid flower visitors of this plant, while it is also a possible host plant for the caterpillars of numerous butterflies including the shockingly beautiful western green hairstreak (Callophrys affinis), the very rare Harford’s sulphur (Colias harford), the Persius duskywing (Erynnis persius), the Afranius duskywing (Erynnis afranius), the Northern Blue (Plebejus idas), the Melissa blue (Plebejus melissa), the Acmon blue (Plebejus acmon), and the Funereal duskywing (Erynnis funeralis).
Note that this graceful and extremely showy little plant is probably in decline in numerous places due to habitat degradation and displacement by invasive species. Despite its struggles, bog bird’s foot trefoil grows nicely in rain gardens and bioswales, around downspouts, and in damp drainage ditches. It is tap-rooted and prefers to live in the ground as opposed to containers. Combine it with various rushes in small constructed vernal pools to add an entirely new ecosystem feature to wild backyard gardens.
How to Use Your Cover Crop & Native Seed Packets
Each seed packet is measured to cover 25 sq ft or 100 sq ft, depending on the size you chose.
Sowing Instructions
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When to sow: Fall is ideal in Portland. The soil is still warm for germination, and fall rains keep seedlings watered. Some seeds (like meadowfoam or clovers) can also be spring-sown.
How to sow:
- Rake the soil lightly to create good seed-to-soil contact.
- Scatter the contents of the packet evenly over the area (don’t worry about perfect spacing).
- Gently press or rake seeds in so they make contact with the soil. Do not bury deeply — most native and cover crop seeds need light to germinate.
- Water: Fall rains usually do the job, but water lightly if the weather turns dry.
What to Expect
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Traditional Cover Crops (rye, peas, fava, daikon, crimson clover, buckwheat, mustard): Grow quickly, protect soil, and build fertility. In spring, chop them down or mow before they set seed. Some (like rye) can also be crimped into a mulch.
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Living Mulches (red fescue, dwarf yarrow, creeping thyme, low clovers): These stay low and provide long-term weed suppression and ground cover. Shear lightly as needed, but they don’t require replanting every year.
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Pollinator Wildflowers (Clarkia, poppy, gilia, flax, meadowfoam, coneflower, blanketflower): Not classic cover crops, but they add beauty and attract bees, butterflies, and beneficial insects. Many reseed naturally.
Spring & Summer Management
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Chop-and-drop: Cut plants at the base and leave them as mulch (peas, fava, clovers).
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Mow: Use on ryegrass or cereals to turn them into quick mulch.
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Crimp: Flatten tall rye or grains at flowering to create a long-lasting weed barrier.
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Shear perennials: Yarrow, thyme, and sedges can be trimmed back after bloom.
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Self-seeders: Flowers like poppy, clarkia, and meadowfoam will often reseed themselves. Leave some seed heads if you want them back next year.
Quick Tips
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Cover crops = soil builders.
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Living mulches = weed suppressors.
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Wildflowers = pollinator magnets.
Tulle or row cover can protect young seedlings from birds and slugs until established.
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