American Gromwell (Lithospermum latifolium)

American Gromwell

Lithospermum latifolium

American Gromwell is a robust perennial herb that grows up to 30 inches tall. It is commonly found in mesic to dry woodlands and shaded riverbanks. The plant features small, pale yellow flowers and rough-textured, lance-shaped leaves. Historically, its hard, nut-like seeds were used for medicinal purposes. It is an excellent choice for woodland gardens and naturalized settings where its deep roots help prevent soil erosion.

Characteristics

Type	Forb
Sun	Partial Sun, Shade
Soil	Clay, Loam, Sand/Gravel, Calcareous
Moisture	Dry, Mesic, Wet
Average Max Height (inches)	22
Suggested Plant Spacing (inches)	18
Bloom month(s)	May, June
Bloom Color or Type	White, Yellow
Dominance	Low

Range Maps

Sowing Information

Sow seed onto a firm, weed-free seedbed. Hand-broadcast seed making two perpendicular passes for even coverage. If planting a mix, broadcast the grass component first and lightly rake/drag it into the top 1/8–1/4" of soil. Next, broadcast wildflower/forb seed and press it into the soil surface (with a roller/cultipacker or the back of a rake) to ensure good seed-to-soil contact. After seeding, apply a very light layer of clean, seed-free straw (or other weed-free, site-appropriate mulch) to reduce erosion and retain moisture without smothering seedlings. A good rainfall or thorough watering will help settle seed and mulch and improve germination.

Planting Information

Dig a hole in your planting site slightly larger than the plant’s root system. When placing the plant into the hole, ensure that the soil line remains consistent with its original level in the pot. Fill in around the roots with the excavated soil, gently firming it to eliminate air pockets. Water the plant thoroughly the same day to promote successful establishment.