Willow trees are a beautiful and familiar feature of our riverside landscape and are very valuable for wildlife. There are approximately 400 willow species worldwide but only a fraction of these can be found in Britain. Historically, they were grown for wood to produce many items including cricket bats. The pliant stems of some species are used in basketry and weaving hurdles. Willows used to be a common sight on wetland areas but due to the decline in demand for willow products and changes in land use, the management of willow trees has changed and there are now fewer mature trees.
Willow trees can grow to approximately 20 metres in height and often have a domed appearance with the main branches growing down in the familiar weeping willow stance. The bark is grey-brown and deeply fissured and in some species contains the active ingredient Salicin which is better known as Aspirin. The leaves are lanceolate to oval in shape. A willow tree will produce either male or female flowers (catkins) in late April or early May. These catkins are pollinated by insects.
Willow trees prefer wet or moist areas and can most commonly be seen growing along riverbanks. They are very effective at stabilising a bank of a fast flowing stream or river but will need careful management if this characteristic is to be utilised.
More mature willows make excellent habitats for a number of different species. A recent survey discovered that 150 different plants were living in or on Cambridgeshire willows. In turn these plants will support a diverse group of insects and provide food for birds. Even living willows feature holes and hollows that make perfect roosting sites for bats and birds. In some cases it is not possible to save a dying tree but this does not mean it has lost it’s appeal to other species. Some insects are known to only live on the rotting interiors of old willows and are now becoming threatened as a result of the removal of dead trees. Although this may be necessary to avoid damage or injury from falling trees, it may be possible to leave standing dead wood in more remote areas. A dead tree can make an interesting landscape feature too due to it’s gnarled character and unusual shape.
The recent decline in demand for willow products and loss of wetland habitat to development and farming has caused a change in how willow trees are viewed. Their value for wildlife is largely unknown by willow owners and therefore they tend not to be managed appropriately. A new advisory leaflet has been produced to outline the benefits of willows and how they can be maintained. Old willow trees can easily become top-heavy and are prone to being blown over in strong winds. To prevent this they should be regularly pollarded. Pollarding involves cutting the trunk at 2-3 metres high or cutting main branches close to the trunk. The tree will then grow new stems from these points. This process can help to prolong the life of a willow.
If you own a willow you can help by ensuring it is managed appropriately. In many cases this will involve pollarding or planting new willows. For information on willow management, download the advisory leaflet below. If you are considering willow management work you may be eligible for funding, a list of potential sources is available here as a Word document.
Willows Leaflet (PDF) Funding Information (Word)
This leaflet was produced by the Green Belt Project, the Cambridgeshire and Peterborough Biodiversity Partnership and the Environment Agency. If you would prefer a hard copy of this information please contact the Green Belt Project on 01954 713530.
Willow trees can be seen along various sections of the River Cam. There are some good examples at Coe Fen, to the south of Cambridge city. From here you can follow the riverside walk to Grantchester and see a variety of bird and plant species too.
Find out about what's been seen on our sightings page, or take a look at details of some of the projects and sites that we work on.
