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 trilobus is one of the western species. It is a small to medium shrub with very distinctive lobed foliage. The yellow flowers occur in late winter through to early summer, conspicuously displayed on the ends of the branches. The flower clusters are around 30 mm in diameter and are followed by the spherical (barrel-shaped) seed pods which remain on the plant for an indefinite period.
Like many western species, I.trilobus is not regarded as suited to humid climates. It performs best in areas with dry summers and well drained soils. A sunny position will produce the best flowering but some shade is tolerated. It will withstand light to moderate frosts.
I.trilobus 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. It is not known whether I.trilobus has been involved in this work but experiments using I.anethifolius or I.dawsonii as rootstocks may be worth pursuing.
Photo: Brian Walters