Salix

Willows are a wide ranging genus of trees and shrubs with some becoming noble tall trees, whilst others remain prostrate alpines. They have an ability to grow in many temperate environments, including waterlogged ground. Some are grown for their colourful stems, others for showy catkins, both at their best in winter through spring. Shrubs can be coppiced or pollarded every couple of years, around March time. Salix have alternate leaves and buds, whilst the similar Cornus have opposite leaves and buds.

A huge and complex genus that encompasses many varieties and hybrids, one thing shared by all willows is their pollen-rich male catkins, and both male and female catkins with nectar-glands. Together this creates a hugely valuable resource to insects that emerge early in the spring, and need a rapid hit of food to get going with the business of breeding. Goat willow S. caprea is one of the most important pollen/nectar sources in our landscape. The leaves of most species are very palatable to the caterpillars of moths, including such dramatic species as poplar Hhawk-moth, while S. caprea feeds our most majestic butterfly purple emperor, a species that is currently spreading and becoming a real possibility as a garden butterfly. The leaves also host a number of distinctive and fascinating galls, often caused by sawflies. Bushy forms provide bird nesting opportunities; creeping forms provide shelter for beneficial invertebrates; and the dead wood of larger trees provides for numerous rotting fungi and boring beetles.