Scutellaria galericulata aka Marsh Scullcap

Scutellaria galericulata, or common skullcap, belongs to the mint family, Lamiaceae. It is a herbaceous perennial from the temperate Northern Hemisphere. Its native range includes Britain, Ireland, Asia and North America. Wild plants grow beside streams, in wet meadows and fens. They grow in both acid and lime-rich soils. These damp habitats guide its use in gardens.

The plant forms clumps but can spread fast. RHS gives a garden height and width of 1.6–3.3 feet [0.5–1 metre]. Its shorter account gives a height near 2.3 feet [0.7 metres]. Plants reach their full size in one to two years. The green leaves range from rounded to narrow and oblong. Some have hairs, while others have smooth surfaces. The foliage dies back rather than staying green through winter. Green stems carry a purple tint.

Blue flowers appear from June to September. Each has a paler lower lip, with white near the base and centre. They bring summer colour to wet ground near water. RHS suggests this species for wildlife gardens and wildflower meadows. Its quick spread is worth bearing in mind when choosing neighbours. PFAF does not flag it as a weed, despite that vigorous growth.

Grow common skullcap in full sun or part shade. It needs soil that stays damp throughout the year. Clay and loam suit it, including sites with poor drainage. It accepts acid, neutral and alkaline soil. Pond margins and stream banks offer suitable planting sites. The crown can sit beneath 0.07 feet [0.02 metres] of water. RHS rates its cold hardiness H7; PFAF lists USDA zones 4–8. Divide plants in spring or autumn, or sow seed in autumn. Cut away old growth at the year's end. RHS lists no other pruning needs. Aphids may attack, but disease is not usually a problem.

PFAF records no known food use for this species. It also lists no known hazards, though this does not prove safety. The same source records herbal use for throat infections. It also describes uses for inflammation, spasms and fever. It notes that herbalists seldom use this plant. These records describe past uses, not proof that treatments work. They do not establish a safe dose for home use. PFAF lists no other uses beyond its medicinal record.