The hazel has both male and female flowers on each shrub, and the two flowers are quite different. The male flowers are gathered within the long, breeze-blown catkins and these are by far the most prominent. Each catkin is made up of many individual flowers – these are the small green/yellow male flowers which produce the pollen.

The hazel is wind pollinated and the pollen from the catkins blows to reach the female flowers which you would never spot unless you looked carefully – they are tiny individual flowers, visible only as red styles protruding from a green bud-like structure on the same branches as the male flowers. Once pollinated in the springtime, the female flowers set to work producing the hazelnuts which ripen in the autumn.