Banksia serrata

old man banksia
Shrubby gnarled tree develops characteristic ‘old man’ bark with age. Cream yellow flowers fade to brown, then produce furry cones. Prune to shape after summer blooms. Provide good drainage and low fertilizer with no phosphorus. 
height 12–35ft
width 6–12
tolerates Coast, Drought, Deer , Salt, Wind
water
needs		 Low – Moderate
water
info		 Banksia are from mediterranean climates of Australia and adapt well to California, particularly along the coast. They appreciate good drainage, but are somewhat adaptable to heavier soil as long as watering is infrequent (once established) and they are in a sunny spot. Once established they will grow and look their best with deep watering every other week to once a month during summer. If they have sharp drainage they will tolerate even more water.
hardy
to		 22F
exposure Part Shade – Full Sun
indoor
outdoor		 Outdoor
drainage In Ground: Cactus Mix, In Pots: Cactus Mix, Tolerates Sandy Soil
fertilizing Bloodmeal, Fish Emulsion, Low Needs, No Phosphorus
origin SE Australia
california
native		 No
sunset
zones		 14–17, 21–24

Sunset Zones Map

Outdoor Exposure Guide

Growing Notes

This banksia has a thick bushy form when young, becoming gnarly and treelike with time, though it can be kept smaller by pruning. Don’t prune more than two years of growth or you risk the plant not budding back. You can also prune off lower branches to force a more treelike form, this is best started early.
Banksia prefer mildly acidic soil, and if your PH is on the high side you can add cottonseed meal or chelated iron to lower it. Generally the best rule is to not fertilize them unless they aren’t growing or are turning yellow. In this case you can try nitrogen fertilizer in the form of fish emulsion or blood meal, but never give them any significant phosphorus and avoid potassium.
While this plant grows unto forty five feet tall in nature, thirty five feet is the tallest we have ever seen them growing in California.

Special Interest

Occurs naturally on the east coast of Australia from southern Queensland to Victoria. Also grows in northern Tasmania.

Excellent cut flowers and foliage.