PLANT OF THE WEEK

Banksia ericifolia and Banksia spinulosa: what's the difference?

Scientific Name: Banksia spinulosa

Common Name: Hairpin Banksia

Family: Proteaceae

Plant height: Mostly a multi-stemmed lignotuberous shrub. Varies greatly in height 1 -3 m 

Position: Full sun, frost hardy including Canberra winter frosts.

Leaves:long and narrow, 3-8 cm long by 2-7 mm wide, and variably toothed. Leaf margins often recurved which is an adaptation to dry environments.

Flowering:The flower spikes range from 10-20 cm in length. A spike may contain hundreds or thousands of individual flowers, each of which consists of a tubular perianth made up of four united tepals, and one long wiry style.

Position: Prefers to grow in the open where it makes a nice rounded shrubs.

Shade makes it spindly.

Banksias are an import source of nectar during autumn and winter when flowers are scarce.

Scientific Name: Banksia ericifolia

Common Name: Heath Banksia

Family: Proteaceae

Plant height: Mostly a multi-stemmed shrub. Varies greatly in height 3-6 m

Position: Full sun, frost hardy including Canberra winter frosts.

Leaves: The linear dark green leaves are small and narrow, 9–20 mm long and up to 1 mm wide, generally with two small teeth at the tips. 

The leaves are crowded and alternately arranged on the branches..

Flowers: cylindrical flower spikes are quite large at 4-6 cm wide and up to 30 cm long

Differences: Banksia ericifolia has much narrower leaves and is fire-sensitive in that it does not have a lignotuber for vegetative regeneration after bushfires. The species relies on seed for regeneration - seeds are retained in the cones for many years and are released by the heat of a fire.

Pruning:

People are afraid to prune Banksias because they think of them as being a bit tricky.
If you’re not sure what type of Banksia you have, then only light pruning.
If you know your Banksia has a woody rootstock (lignotuber) then it can be heavily pruned.

•  Only low phosphorus fertilisers should be used if at all. I’d recommend Blood n Bone.

Here's an interesting tidbit: Historically B. ericifolia is supposed to be the first specimen collected by Sir Joseph Banks at Botany Bay in 1770. 

For some reason, Banks did not describe this new discovery however and it was left to Carl Linnaeus who later named the genus Banksia in honour of Banks in 1782.

Have a listen to the podcast.

I'm talking with Adrian O’Malley, qualified horticulturist and avid native plant expert.