The root is almost cylindrical, very slightly twisted and tapering and often crowned with a tuft of grey hairs. Externally it is brown and wrinkled, with bright black spots. The fracture is short, and the transverse section, magnified, presents a beautiful radiate structure and many oleoresin glands. The taste is pungent and odour slight. Any ordinary good soil is suitable, but better results are obtained when it is well-drained, and of a stiff loamy character, enriched with good manure.
Propagation is done in three ways, by seed, by division of roots and by cuttings.
If grown by seed , sow in February or March, thin out to 2 to 3 inches between the plants, and plant out early in June to permanent quarters, allowing a foot or more between the plants and 2 feet between the rows, selecting, if possible, a showery day for the operation. The seedlings will quickly establish themselves. Weeding should be done by hand, the plants when first put out being small, might be injured by hoeing. To propagate by division , lift the plants in March, or whenever the roots are in an active condition, and with a sharp spade, divide them into three or five fairly large pieces. Cuttings should be made from the young shoots that start from the base of the plant, and should be taken with a heel of the old plant attached, which will greatly assist their rooting.