Propagation
Fresh seed should be sown in a well-drained media and the kept moist but not wet. Maintain a temperature of 18º to 21º C. (64º to 75º F) in an unheated glasshouse or open frame.
Germination occurs within 26-days to 40-days and should be prick out and pot up when large enough to handle. Careful not to over water seedlings, as they are prone to damping off and larger plants are difficult to transplant.
When removing seed from Banksia fruits it may be necessary to place the fruit in an oven for 60 minutes at a temperature of 120° C. to simulating the effect of a bushfire to opening the valves.
Note:
It may be difficult to grow in the eastern states Australia, requiring a limestone underlay in the soil and a mediterranean climate with dry summers.
Botanic information
Leaf: The leathery textured narrow oblong leaves are up to 40 mm (1? in) wide. Theyhave serrated margins and an obtuse apex with a short petiole.
Flower: The small tubulate flowers have orange perianth segments are up to 40 mm (1? in) long and are silky pubescent on the outside and the protruding curved pistil is up to 41 mm (1? in) long.
The flowers are arranged densely in a terminal cylindrical spike that is up to 120mm (4µin) long by 80mm (3? in) wide and accompanied by bracts at the base. They appear from late summer to winter and old flowers soon fall from the plant.
Fruit: There is up to 25 narrow obovate beaked follicles that are up to 15 mm (?in)wide that are smooth with a fine pubescent. They are arranged densely in a woody cluster opening when mature to release smooth obovate seeds up to 30 mm (1? in) long by 14 mm (? in) wide and have a curved notched wing to 25 mm (1 in) wide.
General pruning information
When pruning reduce only the new growth as cutting old wood is likely to cause dieback. Limbs may be removed back to the collar.
Cultivation
Generally, Banksia species prefer a well drained, sandy soil that is tending acidic but many species from Western Australia grow on acidic top soils with alkaline subsoil.
When the growing Western Australian species outside their native habitat technique of building a garden bed, of acidic soil above a layer of agricultural lime commonly produces better results particularly in raised garden beds or on slopes. During establishment, keep the soil moist but not wet and do not use fertiliser that contains phosphorus.