Banksia robur, Swamp Banksia, is a shrub reaching a height of two metres with multiple stems arising from a lignotuber (swollen root mass).
Bark is smooth and the branchlets are covered with tangled, rusty hairs. The leaves are large, with toothed margins, glossy green above and light green beneath.
Large flower spikes carry tightly packed metallic green flowers. In bud they are bluish green. Spikes persist after they dry for many months. They appear from January to July. Flower spikes are carried terminally or along older branches. Terminal flower spikes are held above rosettes of the large leaves.
Banksia robur is a native of the Central and North Coasts of NSW and Southern Queensland where it is found in permanently damp sites. In these sites they are often the most visible plants.
As the common name implies this species is usually found in permanently moist situations. In the garden plants will thrive in well drained situations as long as they are adequately watered. Perhaps in these situations gardeners should take out some “polypipe insurance”. When planting place a 30 centimetre length of polypipe in the planting hole with half the pipe buried beside to plant. During watering fill the pipe a few times. This directs the water directly to the roots. We use this watering system with all our banksias.
Propagate from seed. B. robur is said to flower 3-5 years from seed.
The species name means strength and probably refers to the robust growth habit of the plant.