Propagation
Sow fresh seeds during spring in boxes and prick out when large enough to handle.
Divide established clumps during spring.
Take soft tip cuttings of non-flowering shoots during early spring.
Botanic information
Leaf: The narrow mid-green lanceolate leaves have deeply veined upper surface and are arranged in opposite pairs. They are sessile and when crushed are slightly aromatic.
Flower: The small purplish tubulate flowers are arranged in a whorled spike-like terminal cyme that appears above the foliage on a tall scape during midsummer. The flower colour is occasionally yellow in the wild.
Fruit: The small nut contains viable seed that may self seed but the plant is normally reproduced vegetatively.