Propagation
Sow fresh seeds when ripe with a single seed in each container with a well-drained gritty medium. the seeds are difficult to germinate and may take some time.

Root cuttings taken during winter or division of offsets during spring.

Botanic information
Leaf: The pinnatifid leaves are linear to oblong with undulating serrated margins that are armed with pungent spines. The upper surface is glossy dark green and the underside is pale green with a prominent mid-rib and when crushed are aromatic. 

Flower: The tubulate flowers have green-bronze sepals and a long pubescent tube with a 5-lobed corolla that is almost 2-lipped. The flower colour varies from white to pink then red when fertilise. 

They are arranged in dense whorled spike that is accompanied with bronze-tinged leaf-like bracts with spiny tipped serrated margins. The spike is held up of the foliage on a leafy scape that is up to 1 m (3 ft) tall and appears from the centre of the plant during summer.

Fruit: The small achenes are viable but the plant is commonly reproduced vegetatively.