Hakea costata is a small to medium shrub which may reach 2 metres high but is usually smaller to about 1 metre. Leaves are linear, up to 12 mm long x 3 mm wide with a sharp point. The stems are covered with dense hairs, particularly when young. The white flowers occur in the upper leaf axils and are very prolific, giving the appearance of white candles. They are generally seen in late winter to spring. The flowers are followed by woody seed pods about 12 mm long containing two winged seeds, the usual number for all Hakea species. The pods do not shed the seed until stimulated to do so by environmental conditions (eg after a bushfire).
This very spectacular species is not in general cultivation, possibly due to lack of availability of seed. It is best suited to areas of low summer humidity and is likely to be difficult to maintain in humid areas. It is grown successfully at Burrendong Arboretum in the cental west of New South Wales. The species is tolerant of at least moderate frosts and is best suited to an open, sunny position.
Hakea costata should be easily grown from seed. Cuttings may succeed but will probably be difficult to strike. It is not known whether grafting has been attempted with this species but, if successful would be a way to grow this very attractive plant in a wider range of climates. Many Hakea species have been successfully grafted onto H.salicifolia root stock.
Photo: Murray Fagg – Australian National Botanic Gardens