https://defrafarming.blog.gov.uk/sustainable-farming-incentive-pilot-guidance-maintain-trees-along-field-boundaries/
Maintain trees along field boundaries
The guidance on this page is for SFI pilot participants only. Please visit GOV.UK for the official Sustainable Farming Incentive scheme guidance.
Find out how land managers can manage trees along field boundaries and how this can benefit the environment.
If you’re completing this action as part of the Sustainable Farming Incentive pilot, how you do it is up to you.
The advice on this page can help you get better environmental and business benefits, but you do not have to follow it to get paid.
Why you should manage trees along field boundaries
Trees are found in and alongside field boundaries such as:
They can be:
- lines of trees or shrubs, where scrubby hedges have been allowed to grow unchecked
- standard trees that have been specifically planted or selected to develop to maturity
Trees are being lost from the landscape faster than they are being replaced. Pests and diseases like ash dieback have increased the rate of loss. Unless existing trees are retained and managed well, the landscape could profoundly change.
Where to manage trees along field boundaries
It’s particularly important to manage boundary trees that:
- connect hedges or other habitats, like woodlands, wood pasture and orchards
- support other features, like species-rich hedges, ditches or banks
- are in hedgerows that are surviving fragments of ancient woodland, and contain rare ancient woodland plants, mosses and lichens
- are in hedgerows that contain veteran or ancient trees with significant veteran features and dead wood habitat
- are of landscape or historic interest, like parish boundaries, within Areas of Outstanding Natural Beauty or national parks
There may be situations where you do not want full-grown boundary trees. For example, you might want to heavily prune (pollard) willows around fields that are important for ground-nesting birds.
Benefits of managing trees along field boundaries
Boundary trees are important structures in the landscape. They provide many environmental benefits for the small area they take up.
Mature boundary trees generally have full, open-grown crowns, unshaded by other trees. This makes them particularly important for lichens and the species that feed on them. They also create a wide range of habitats, different to those of woodland trees. Old trees containing dead and decaying wood are the most important for wildlife.
Boundary trees can benefit your business. They can:
- provide food and shelter for livestock and crops, boosting their health and yield
- supply wood for timber and fuel
- provide a source of fruit and other ingredients for food and drink
- screen unsightly developments and protect privacy
- boost populations of beneficial insects which can pollinate crops and help control pests and diseases
They benefit wildlife, by providing:
- food, shelter and breeding sites for a range of wildlife, including dormice, birds and bats
- an important source of dead wood, an essential habitat for many rare and threatened species of insect, fungus and lichen
- pollen and nectar for bees and other pollinators
There are also wider environmental benefits. They can:
- improve air quality, by removing particles and pollutants from the air
- absorb carbon dioxide from the atmosphere and store it in their wood
- contribute to the character and appearance of many of our most valued landscapes
- have historic importance, as they can be many hundreds of years old and form traditional parish or farm holding boundaries
It takes many years to develop replacement hedgerow trees. If you do not have these on the holding or in the local landscape, you can establish new trees.
How to manage trees along field boundaries
Protect your trees from damage
Prioritise protecting trees, not cutting them back or down. Protect existing hedgerow trees from damage to their trunk, crown and roots.
Prioritise managing veteran trees and trees with dead and decaying wood, as they support the most wildlife. Old trees may be stag headed (where the outer branches die and stick out beyond the now-reduced crown) but this is natural and can still be healthy.
Most tree roots grow in the top 30cm of soil. They may spread to up to twice the width of the canopy. Over time they develop beneficial associations with fungi called mycorrhizae. These help the tree by extracting nutrients and other elements from the soil.
Establish a root protection area around each tree, to prevent actions that could physically damage the roots or the soil structure. This should be whichever is the larger of:
- 15 times the diameter of the tree trunk (about 1.5 metres from the base)
- 5 metres beyond the canopy
Manage the sward within the root protection area appropriately. You should:
- protect trees, particularly veterans, from changes in land use like grazing land converted to arable
- control scrub and tall vegetation, as these can compete with the tree roots
- consider applying a mulch like wood chips, which can relieve soil compaction and control weeds
- not use fertilisers, pesticides, herbicides, lime or manure, as they can encourage rank vegetation growth and break the mycorrhizal fungi association with the roots
Livestock can damage trees by compacting soil and stripping the bark. You should:
- keep livestock numbers at a level which prevents these issues, but still controls scrub and rank vegetation
- place feed and water troughs outside the root protection area to discourage livestock from gathering beneath the tree canopy
- consider using a livestock-proof barrier like fencing or dead hedging, either around the root protection area or around the tree trunk
Avoid causing damage with farm machinery. Relocate tracks outside the root protection area where necessary.
Do not:
- plough, harrow or cause any other mechanical disturbance
- use equipment that’s too heavy
- use equipment when the soil is wet
- damage trees when you cut hedges or scrub
Prune trees and manage dead wood
Do not cut back a tree unless there’s a clear need. This may be:
- to prolong the life of the tree, for example to prevent it blowing over
- for health and safety reasons, like removing branches that pose a risk to people
- because it’s a tradition in the local landscape, for example coppicing or pollarding willow
If you do need to prune existing trees, you should:
- keep pieces of dead wood either attached to the tree, lying on the ground under the tree, or in a pile nearby
- leave standing dead trees as they are, as they provide valuable wildlife habitat
- employ a qualified tree surgeon to carry out any pruning work
When to prune trees along field boundaries
Ideally, manage trees in the winter months when they are dormant. You can start work in the autumn, once most deciduous species have started to shed leaves. You should stop before they begin active growth in the spring.
You can cut trees to provide tree hay for livestock when the leaves are green. You can maintain trees for safety reasons at any time.
Before you start work:
- check with your local authority if any trees are subject to a Tree Preservation Order or in a conservation area
- talk to the park authority if you’re in a national park
You may have trees growing in a hedgebank that’s a scheduled ancient monument. Talk to Historic England if the tree is causing concern about the condition of the monument.
You may need a Forestry Commission felling licence if you are either:
- planning to remove trees
- managing overgrown hedges (when felling more than 5 cubic metres of timber in a calendar quarter)
If you identify tree disease you may need to do remedial work, and even fell the tree if you have safety concerns. Some diseases mean you are legally required to remove the tree. Find out which diseases are notifiable and how to contact the Plant Health Helpline to report these diseases.
Birds, nests and eggs are protected by law. Only carry out work on existing hedges outside the bird breeding season, which is usually from 1 March to 31 August. Also check for bat roosts.
What well managed trees along field boundaries look like
Where field boundary trees are well managed, you’ll see:
- a diverse mix of healthy mature trees that are native to your local area, at appropriate spacings along the length of the boundary
- trees with no signs of bark stripping, compaction under the canopy or any other damage
- younger trees with healthy crowns and good annual growth
- older trees that support wildlife and continuity, as well as a range of other ages and species, to provide successors
Trees respond slowly if you attempt to restore them to health. It may take several years to notice an improvement in tree health.
You should be able to keep boundary trees for many years as living trees and later as dead wood.
