Isopogon is a genus of around 35 species, all occurring only in Australia. They are found in the southern half of the continent in temperate regions. Most are small to medium sized shrubs having flower clusters arranged in globular heads. The fruits are also globular in shape giving rise to the common name of “drumsticks”. Some are also called “coneflowers” although this name is more usual in the related genus Petrophile.
Isopogon formosus is one of the western species. It is a small to medium shrub up to 2 metres high. The leaves may be up to 40-50 mm long and are divided into many narrow segments. The deep mauve to pink flowers occur in winter and spring, conspicuously displayed on the ends of the branches. The flower clusters are around 50 mm in diameter and are followed by the spherical (barrel-shaped) seed pods which remain on the plant for an indefinite period.
This is a very spectacular species which is well known in cultivation in Mediterranean-type climates (dry summer – wet winter). In more humid, summer rainfall areas the species is difficult to maintain in cultivation. It requires well drained, moist soils in a sunny position or lightly shaded position. It will withstand light to moderate frosts.
I.formosus is usually propagated from seed which germinates readily without pretreatment. Cuttings are also successful using firm, current season’s growth. Some limited work has been carried out by enthusiasts on the grafting of western species of Isopogon, onto eastern rootstocks to extend the range where the plants can be grown. This offers the best chance for successful cultivation in humid areas.
Photo: Brian Walters