 Like many members of the family Proteaceae, Banksia menziesii is largely self-incompatible; that is, inflorescences require pollinators to be fertilised and produce seed. One mechanism by which the species promotes cross-pollination with other plants is protandry, whereby the male parts release pollen that becomes non-viable before the female parts become receptive on the same flower spike. The individual flowers are uniform, and it is unclear why so few go on to develop follicles. Published in 1988, a field study conducted in banksia woodland near Perth noted that anthesis occurred on an inflorescence at an average rate of 40 to 60 florets opening per day, although this varied widely between different flowerheads. Foraging by honeyeaters would cause the florets to open, but bees would not.
