Tree pollarding is a pruning technique that has been used for centuries to manage the growth of trees. It involves cutting back the branches of a tree to promote new growth and maintain its shape. Pollarding is often used on trees that are too large for their location or that have become overgrown. In this blog post, we’ll explore the science behind tree pollarding and discuss the benefits of this pruning technique.
The Science Behind Tree Pollarding
Tree pollarding is a pruning technique that involves cutting back the branches of a tree to a uniform height, usually leaving only a few feet of the trunk and some stubs. This practice stimulates the growth of new shoots from the cut ends, creating a dense and rounded canopy of foliage. Tree pollarding has several benefits for both the trees and the people who manage them.
The benefits of tree pollarding include:
- Size control: Pollarding prevents trees from outgrowing their space, especially in urban areas where they may interfere with power lines, buildings, or other structures. Pollarding also reduces the weight and wind resistance of the tree crown, making it less likely to break or fall during storms.
- Wood production: Pollarding can provide a regular supply of firewood, fence posts, or other small-sized timber products. Some trees, such as willows and poplars, can produce multiple harvests of wood in a single year after pollarding.
- Foliage production: Pollarding can enhance the ornamental value of trees by producing lush and colorful foliage. Some trees, such as beeches and limes, can retain their leaves longer after pollarding, creating winter interest. Pollarding can also increase the production of flowers, fruits, or nuts in some species.
- Health improvement: Pollarding can improve the health of trees by removing diseased, damaged, or dead branches. It can also reduce the risk of pest infestations or fungal infections by improving air circulation and sunlight penetration in the canopy.
The science behind tree pollarding is based on the ability of some trees to produce new shoots from dormant buds that are hidden under the bark. These buds are activated by the removal of the apical dominance of the main stem or branch, which inhibits their growth. The new shoots grow rapidly and vigorously from the stored carbohydrates in the roots and trunk of the tree.
The process of tree pollarding involves several steps:
- Selection: Not all trees are suitable for pollarding. The best candidates are those that have a strong regrowth potential and can tolerate repeated pruning. Some examples are willows, poplars, oaks, beeches, chestnuts, and limes.
- Timing: Pollarding should be done when the tree is dormant, usually between winter and early spring. This reduces the risk of bleeding sap or infection and allows the tree to heal before the growing season.
- Cutting: Pollarding should be done at a consistent height above the ground level, usually between 6 to 10 feet. The branches should be cut close to the trunk or stubs, leaving no more than an inch of stub. The cuts should be clean and smooth to prevent decay or disease entry.
- Maintenance: Pollarding should be repeated regularly to maintain the desired size and shape of the tree. The frequency depends on the purpose and species of the tree, but generally ranges from once every two to five years. Failure to maintain pollarding can result in weak and heavy branches that may break or damage the tree.
Tree Pollarding Techniques
Tree pollarding is a pruning technique that involves cutting off the central leader and all the lateral branches of a tree to a certain height, usually within a few feet of the crown. This creates a dense mass of new growth at the end of each branch, giving the tree a distinctive appearance. Pollarding is done for various reasons, such as controlling the size and shape of the tree, preventing interference with power lines or buildings, producing fodder or firewood, or enhancing the ornamental value of the tree.
Different techniques are used in tree pollarding, depending on the species, age, and condition of the tree. Some of the common techniques are:
- Heading back: This involves cutting back all the branches to a uniform length, leaving stubs that will sprout new shoots. This technique is suitable for young trees or shrubs that have not been pollarded before.
- Thinning out: This involves removing some of the branches completely, leaving others intact. This technique is suitable for older trees that have been pollarded before and have developed thick pollard heads. Thinning out reduces the weight and stress on the branches and allows more light and air to reach the inner parts of the tree.
- Crown lifting: This involves removing the lower branches of the tree, leaving only the upper ones. This technique is suitable for trees that need to be kept away from grazing animals or pedestrians. Crown lifting also improves the visibility and aesthetics of the tree.
To choose the right technique for your trees, you need to consider several factors, such as:
- The purpose and goal of pollarding
- The health and vigor of the tree
- The natural growth habit and shape of the tree
- The time of year and frequency of pollarding
- The availability and cost of professional services
Conclusion
Tree pollarding is an ancient and useful pruning technique that can help you manage the size and shape of your trees, as well as provide you with various benefits, such as fodder, firewood, or ornamental value. However, pollarding is not suitable for all trees, and it requires regular and careful maintenance to keep the trees healthy and attractive. If you decide to pollard your trees, make sure you choose the right species, technique, and timing, and consult a professional arborist if you have any doubts or concerns