Banksia seminuda

river banksia
Fast growing, adaptable, upright tree is one of the largest banksias. Blooms early with showy yellow to red flowers. Tolerates clay and over-watering better than other banksias.
Banksia seminuda
height 25–45ft
width 15–30ft
tolerates Coast, Cool Summers, Drought, Deer , Fog, Wind
Low – Moderate
Banksias 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. The river banksia tolerates moderately moist soils if water does not stagnate.

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.
exposure Part Sun – Full Sun
drainage In Ground: Cactus Mix, In Pots: Cactus Mix, Tolerates Sandy Soil
fertilizing Bloodmeal, Fish Emulsion, Low Needs, No Phosphorus
origin SW Australia

Sunset Zones Map

Outdoor Exposure Guide


Full Sun
Six or more hours of sun beams directly landing on the plant's leaves.

Part Shade
Three to five hours of sun beams directly landing on the plant's leaves.

Part Sun
One to two hours of sun beams directly landing on the plants leaves.

Full Shade
The plant is never fully lit by sun beams, but is in a bright spot or has dappled sunbeams playing over the leaves throughout the day.

Deep Shade
The plant never has dappled light on the leaves, and is in a place that feels dim, even on a nice sunny day.


Growing Notes

This plant shoots up quickly (even without fertilizer) and then begins filling out over many years. Thin out the inside to create a more treelike open form. This species tends to make the most classic tree form of all the banksias we grow.
Banksias prefer mildly acidic soil, and if your PH is on the high side you can add cottonseed meal or chelated iron to lower it. They appreciate nitrogen in the form of fish emulsion or blood meal, but never give them any significant phosphorus and avoid potassium.

Special Interest

Our staff have found this to be one of the most forgiving banksia in their own gardens. It tolerates dreary winters with drenching month-at-a-time rainstorms. It is adaptable to high or low levels of watering, not surprising considering that it typically grows along rivers.

One of our most trusted growers commented that the only issue he’d encountered with the plant was that bucks liked to rub their antlers on it in the spring, but that it seemed to be recovering from this damage as well. Well, at least we know deer won’t eat it!