Description Isodon effusus Isodon effusus is a striking herbaceous perennial from the mint family, native to Japan and parts of East Asia. This robust plant typically reaches heights of 90-120cm, forming an upright, bushy clump with strong, square stems characteristic of the Lamiaceae family. The foliage is attractive, with deep green, ovate leaves. In late summer to autumn, it produces elegant sprays of small, tubular flowers in shades of pale blue to lavender, which are highly attractive to bees and other pollinators. Culturally, Isodon effusus thrives in partial shade to full sun and prefers moist, well-drained, humus-rich soil. It’s hardy to around -15°C, making it suitable for most UK gardens. Water regularly during dry spells, particularly in summer. The plant benefits from an annual mulch of organic matter in spring. Cut back dead stems in late winter or early spring to encourage fresh growth. Propagate by division in spring or from softwood cuttings in early summer.
