A bushy shrub to small tree capable of reaching 6 metres tall in the wild and a spread to 4 m. It is found naturally on sand deposits and sandstone in dry sclerophyll woodlands and gully forests and ridgetop woodlands as well as coastal heaths and shrublands where it can dominate and form dense impenetrable stands. It is also found on heavier clayey soils or where clay has infiltrated sand and sandstone deposits, and can grow in swampy wet conditions. It is found mainly along the coast and into the Blue Mountains, north from Jervis Bay, to south-east Queensland.
The leaves are alternate to pseudo-whorled, heavily clustered along the stems, linear, to 20 mm long and only 1-2 mm wide, dark green above and lower surface much paler with dense hairs. The leaf apex is distinctively toothed or notched, which helps when identifying seedlings and small plants.
The inflorescences of banksias are generally referred to as spikes or a spike-like structure which consists of fused racemes of paired flowers (hence it gets referred to as a conflorescence). There can be 100s of flowers in each spike. The flowers of banksias have 4 tepals (petals or sepals) in a tubular formation, 4 anthers hidden inside and an elongated carpel (female part) where the style and extends outwards forming the edge of the spike (somewhat similar to individual grevillea and hakea flowers).
In this species, the spikes are generally to 20 cm long but can be up to 40 cm, and up to 10 cm wide, with each flower thin but up to 5 cm long, bright orange (gold-orange) to burnt orange to red-orange in some populations.
The spike then turns into a cone-like structure of follicles; a fruit which splits open on one side. Each follicle has one or two winged seeds which is actually a fruit in itself called a samara. The follicles can take a long time to mature and open, usually needing a fire. Each “cone” can produce a fair amount of seed with this species follicles to 20 mm long.
A popular plant in the garden with one general advantage in that it can grow on clay and moist soils (although may not do as well). Reported to be a relatively easy plant to grow if it establishes well. It can grow into a large shrub and spread widely so allow some room. Can produce copious flower spikes which attract birds.
Plant in a sunny spot and allow for drainage but will tolerate some moisture. Many banksias benefit from growing on a slight slope. Do not mulch too heavily and try to keep grass away from the trunk. Very hardy once established. It is excellent for attracting honeyeater and other birds.
Slow growing but will grow consistently if happy and will form a very nice shrub after a few years. Will likely grow to about 4 m in a garden (although this will take time) and tends to spread widely, so allow some space. Very suitable for sandy gardens.
Do not apply a high phosphorus fertiliser as Proteaceae are generally sensitive.
Prune after flowering or harvest cut flowers. Can be trained into a denser shape with periodic pruning. Reported to tolerate frost.
Susceptible to Phytophthora and any other root rotting fungus.
Propagation from seed is very reliable and not too difficult. Aerial layering can also be done.
Two subspecies are currently recognised in NSW: subspecies ericifolia and macrantha.
Subspecies macrantha has longer flowers and seedling leaves with less teeth and grows on the North Coast. Subspecies ericifolia is confined to the Greater Sydney Basin.
A popular hardy cultivar is ‘Giant Candles’ which is a hybrid between B. ericifolia and B. spinulosa.
This species is an obligate seeder – it can only regenerate from the seed bank after fire. Research has been done that this species takes up to 8 years to produce flowers – providing information as to appropriate fire regimes in coastal heaths and shrublands.
Banksia – named in honour of Joseph Banks (1743 – 1820), famous naturalist and botanist on the Endeavour and other expeditions, and President of the Royal Society for over 40 years. The genus was named in his honour by Linnaeus filius (Carl von Lynne – the Younger, son of the famous Carl von Lynne (Linneaus)).
ericifolia – Latin for having leaves resembling the genus Erica – generally referred to as “heaths” – plants of the Ericaceae family.
Not considered to be at risk in the wild. Very common