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 to 47 days and prick out when large enough to handle and pot up. 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.
Botanic information
Leaf: The dark green leathery textured oblong leaves have an emarginate apex and a short petiole up to 8 mm (? in)long. The serrated margins have pungent tips and young leaves are densely tomentose becoming glabrous as they mature.
Flower: The small tubulate flowers have yellow perianth segments are up to 35 mm (1? in) long and are glabrous on the outside and the protruding curved S-shaped pistil is up to 50 mm (2 in) long.
The flowers are arranged densely in a terminal cylindrical spike that is up to 200mm (7µin) long by 100mm (4 in) wide with bracts at the base. They appear from late winter to spring and the old flowers persist on the plant.
Fruit: There is up to 50-broad elliptical smooth follicles that are up to 16 mm (?in)wide and are covered in fine tomentose. They are arranged densely in a woody cluster opening after fire to release smooth obovate seeds that are up to 14 mm (? in) long and have a notched wing to 20 mm (µ 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.