Banksia robur is a spreading shrub to 2.5 m wide and potentially 3 m high, although it can get a little larger in cultivation. It is grown for its leaves as well as flowers. Leaves are very large and leathery textured with serrated margins up to 30 cm long and 10 cm wide. The new growth is colourful, in shades of red, maroon or brown with a dense felt-like covering of brown hairs. Flowers are cream-yellow in the iconic banksia cone-shaped inflorescence.