Veronicastrum virginicum aka Culver's Root

Veronicastrum virginicum is a tall perennial known as Culver's root. It belongs to the plantain family, Plantaginaceae. Its native range spans central and eastern Canada and the United States. It grows in open woods, thickets, moist meadows, and prairies. In gardens, it forms upright clumps with a fine texture. It loses its leaves at the end of the growing season.

Plants reach 3–7 feet [0.91–2.13 metres] tall in bloom. They spread 2–4 feet [0.61–1.22 metres] across. RHS gives a higher upper height of 8.2 feet [2.5 metres]. The green stems are round, smooth, and free of scent. Narrow, pointed leaves grow in rings around each stem. Each ring holds three to seven leaves. The simple green leaves have toothed edges and no hairs. They can reach six inches long.

Tall flower spikes rise above the leaves from late spring through summer. Chicago Botanic Garden lists the bloom season as May to August. Each spike holds many small flowers shaped like tubes. White flowers are frequent, with pink, lavender, or pale blue also reported. Smaller side spikes branch below the main spike. This gives the flower stems a tiered form. Bees gather both nectar and pollen from the flowers. Butterflies, moths, wasps, and hoverflies also visit them.

Grow Culver's root in moist soil with good drainage. It accepts clay, loam, and sand across a wide pH range. Full sun suits it, though it also accepts partial shade. Some afternoon shade helps in the deep South. Too much shade can make stems lean and need support. Do not let the soil dry out. Growth is moderate, but plants can take years to settle in. Remove faded spikes to help extend flowering. Cutting back after bloom may bring fresh leaves and more flowers. Divide clumps in spring. Sources rate it for USDA zones 3–8 and RHS H7.

Its height suits the back of borders and cottage gardens. It also fits meadow, rain, native, and pollinator gardens. The flowers serve as cut flowers, and plants resist deer. Serious pest problems are uncommon, but aphids may occur. Powdery mildew, downy mildew, and leaf spot are possible. Several Indigenous peoples used the plant as medicine. PFAF reports no known food use and warns of possible toxicity. Fresh roots can cause strong bowel movements and vomiting.