Blephilia hirsuta aka Hairy Wood Mint

Blephilia hirsuta belongs to the mint family, Lamiaceae. This perennial lives for more than two years. People call it wood mint or hairy pagoda plant. It grows wild in eastern Canada. Its range also spans the central and eastern United States. It is not native to Britain or Ireland. In Missouri, it grows in scattered counties across the state. There, it lives in rich, damp woods, on slopes, and in valleys. These wild sites give it shade and moist soil.

Wood mint grows in upright clumps and has square stems. Garden plants reach about 2.5 feet [0.76 metres] tall. They spread about 1.5 feet [0.46 metres] wide. Hairs grow on both the stems and the leaves. The name hirsuta refers to this hairy growth. Leaves on the stems are oval and have toothed edges. They grow on long stalks. Crush the leaves to release a mild scent. The upright shape adds interest in a garden. So do the scented leaves and flowers.

The blue to purple flowers each have two lips. They grow in round groups near the stem tip. These groups form whorls, set at several levels. Gaps between them give the flower spike its tiered look. Fringed bracts form a ring beneath each flower group. The blooms look like those of monardas, their close kin. Missouri Botanical Garden lists blooms from May to September. Its text says late spring to midsummer. Chicago Botanic Garden lists bloom times from May into October. These sources give a broad bloom season, not one fixed span.

Grow wood mint in full sun or part shade. It does best in average soil that drains well. Keep the soil at a medium moisture level. Its woodland roots also link it to rich, moist ground. Both garden sources list USDA hardiness zones 4–8. Missouri Botanical Garden rates its care needs as medium. It suggests gardens of native plants and open woodland gardens. Wood mint also suits wild gardens. Its clump shape fits that style of planting.

Powdery mildew can harm wood mint. Insects also chew its leaves and can spoil their look. Plants may look ragged and untidy by late summer. This wear can make the leaves less of an asset. Weigh this flaw against the showy blooms and scented leaves.