This is another great WA prostrate ground cover Banksia that grows and flowers directly on the ground like Banksia blechnifolia. They have a very similar habit, however their leaves and flowers are quite different.
Banksia petiolaris has a lovely bluish hue to its leaf, in the image above you can see it growing amongst Themeda ‘Mingo’, they make a great pair don’t they?
This Banksia has long slightly serrated leaves which point to the sky, the new branches are soft and furry and the flowers are produced on the tips of these stems . Banksia petiolaris is also from southern WA and enjoys a well drained soil in full sun to part shade, it is also tolerant of alkaline soils.
The flowers begin as red velvety spikes and turn into large cream coloured cones, these come out from Autumn though Winter and reach about 20cm in height.
I have found petiolaris more difficult to grow than blechnifolia, I’m not sure why, it also likes to grow on a non organic surface and needs as little humidity as possible. I’ve definitely found both blechnifolia and petiolaris grows much better for me in dappled light or part shade. This reduces the humidity caused by our hot Summer afternoon sun, my friend’s petiolaris grows like a weed and can be seen in the image below, it is literally growing into the gutter 😉