Propagation
Take stem cuttings from spring to summer. Allow the cuttings to dry and form a callus for 1 to 2 weeks before planting into a very well-drained gritty media.

Surface sow fresh seed during spring, prick out and plot when large enough to handle.
Division of the clump during spring.

Note:
This plant is regarded as a weed in many regions as it can self-sow or spread vegetatively readily and care should be taken when selecting a planting site.
It is regarded as a noxious weed in many places such as Colorado in North America and is difficult to control. It has proven to be harmful to cattle and horses but has no effect on sheep.

Botanic information
Leaf: The bluish-green linear leaves have an acute-mucronate apex and a short petiole. The upper surface has velvet-like appearance and the underside is pale green and they are crowded towards the end of the stems. During autumn the leaves turn yellow before falling.

Flower: The male and female flowers are arranged in a cup-shaped involucre-like organ (cyathia) that has small green-yellow bracts. The male flower has a single stamen and the female consists of a 3-celled pistil. The flowers have a short pedicle and are arranged in a terminal cyme that is up to 200 mm (7¾ in) wide and appear from late-spring to midsummer. 

Fruit: The 3-valve oval capsule is an explosive schizocarp and contains the numerous seeds that are spread for up to 5 m (16 ft). The seeds are very viable but the plant is commonly reproduced vegetatively to maintain true to type.

Note:
Care should be taken when selecting a site as all Euphorbia's contain white sap that causes skin and eye irritation. Be certain to wash your hands with soap and water after handling plant material.