Propagation
Sow fresh seeds during late winter in containers and place in a protected environment. Plant out when large enough to handle with 300 mm (1 ft) spacing.
Division of the clump when dormant.
Botanic information
Leaf: The leaves are ovate to lanceolate or occasionally orbicular with an entire to serrated margin with an obtuse apex and a truncated base. It has a short petiole and the upper surface is dark green and the underside is glandular-pubescent. When crushed the foliage has a mint scent and the leaves are used for medicinal purposes.
Flower: The tubulate flowers have 5-pointed calyx and expanding rose-purple obtuse 2-lipped petals with 4-slightly exserted purplish stamens. The upper lip is erect with 2-lobes and the lower lip is recurved with 3-lobes. The flowers are arranged in a dense spherical cluster that is up to 40 mm (1? in) wide and is accompanied with bracts, and appears in during summer.
Fruit: The 4-small nutlets are arranged in a persistent calyx and the tiny seeds are viable but the plant may be reproduced vegetatively to maintain true to type.