Althaea cannabina aka Palm Leaf Marshmallow

Althaea cannabina, or palm-leaf marshmallow, belongs to the mallow family, Malvaceae. This perennial comes from central and southern Europe to northern Pakistan. It grows in temperate regions and is not native to Britain or Ireland. Recorded habitats include farmed ground and waste land. Gardeners grow it in beds and meadow settings.

The plant stands upright on strong stems above a woody base. Its garden height ranges from 5–8 feet [1.5–2.5 metres]. The RHS description gives a height near 6.6 feet [2 metres]. Its spread reaches 1.6–3.3 feet [0.5–1 metre]. Plants take two to five years to reach full size. The hairy leaves have lobes and can reach 1.1 feet [0.35 metres] long. The plant sheds its leaves rather than keeping them year-round.

Flowers open from midsummer into early autumn. Each bloom forms a cup, with lavender-pink petals and darker pink-purple anthers. Flowers measure about 0.1–0.16 feet [0.03–0.05 metres] across. They grow alone or in small groups on long stalks. These stalks rise from the leaf axils, where leaves meet stems. The tall stems and long flowering season suit mixed flower borders. The RHS also lists cottage gardens, wildlife gardens and courtyard gardens as suitable settings.

Give it fertile soil that holds some moisture but drains well. Full sun gives the best results, though it also accepts partial shade. It grows in clay, loam, sand and chalk soils. It accepts acid, neutral and alkaline ground. A sheltered site suits it, and its strong stems seldom need support. The RHS rates it H7 for cold hardiness. Plants For A Future lists USDA zones 4–8. Routine pruning is not needed. After flowering, growers may cut the stems down to ground level. Seed and division both provide ways to raise more plants.

Flea beetles may attack the plant, and hollyhock rust can cause disease. Plants For A Future does not flag it as weedy. Its stems yield fibre for fine cloth and paper. That fibre is brittle and can tear with little force. The same source records no known food or medicinal uses. It also lists no known hazards. That lack of reported hazards does not establish that it is edible.