Silk oaks (Grevillea robusta) come from Australia’s east coast, but are well established here. Rather too well actually. They’re fast growers and can outcompete native species, in particular ohia trees. In some places, silk oaks will have their trunks ringed to kill the tree in order to give those native species a better chance of survival.

At this time of year, silk oaks are blooming and their orange flowers put on a brilliant display. They look like giant toothbrushes, or rather groups of flowers look like that, for the toothbrushes are made up of many individual flowers. The flowers themselves are popular with birds, bees and other insects, but both the flowers and wood can cause allergic reactions so have to be handled with caution.