How to prune trees to help keep them healthy and safe? The amount of live tissue that can be removed in one growing season depends on the tree size, species, and age.
Why should you prune trees and how do you prune trees?
Its very important to prune your trees safety
Correct pruning procedures create and maintain a strong tree structure, preventing safety hazards.
Maintain natural tree form
Often erratic or vigorous branches grow that change the growth habit of other branches, which results in a misshapen tree. Early removal of these vigorous branches maintains a healthy tree form.
When do you prune a tree?
Damaged, and diseased branches should be removed as soon as possible. Otherwise, the best time to prune is in summer, once the tree has a fully leafed canopy. Some trees, such as maple and dogwood, will bleed sap at this time of year. This bleeding will not harm them.
How to prune trees (young)
Proper pruning is essential when developing a tree with a strong structure and desirable form. Trees that receive the appropriate pruning measures while they are young will require less corrective pruning as they mature.
Keep these few simple principles in mind before starting to prune trees
- Always have a purpose in mind before making a cut. Each cut has the potential to change the growth of the tree.
- Poor pruning can cause damage that lasts for the life of the tree. Learn where and how to prune trees and make the cuts before picking up the pruning tools.
- Trees do not heal the way people do. When a tree is wounded, it must grow over the damage. As a result, the wound is contained within the tree forever.
- Small cuts do less damage to the tree than large cuts. Correcting issues when a tree is young will reduce the need for more drastic pruning later.
Making the cut
- The pruning cut location is critical to a tree’s growth and wound closure response.
- Make pruning cuts just outside the branch collar to avoid damaging the trunk and compromising wound responses. Improper pruning cuts may lead to permanent internal decay.
- If a large branch must be shortened, prune it back to a secondary branch or a bud.
- Cuts made between buds or branches may lead to stem decay, sprout production, and misdirected growth.
Pruning tools to prune trees
Small branches can be cut easily with hand pruners. Cuts larger than one-half inch (1.27 cm) in diameter should be made with lopping shears or a pruning saw.
Hedge shears should be used for shaping hedges only. Do not use shears to prune a tree. Whatever tool you use, make sure it is kept clean and sharp.
Establishing a strong scaffold structure
A good structure of primary branches should be established while the tree is young. These limbs, called scaffold branches, are a mature tree’s framework. Properly trained young trees will develop a strong structure that requires less corrective pruning as they mature.
The goal in training young trees is to establish a strong, central trunk with sturdy, well-spaced branches. This form mimics tree growth in forest settings where outward branching is limited by neighbouring trees.
Some tree species develop some or all of these characteristics naturally, even when grown openly in an urban or park setting. Others may require more frequent attention.
How to prune for tree trunk development
For most young trees, maintain a single dominant leader growing upward. Do not prune back the tip of this leader or allow secondary branches to outgrow the main leader.
Sometimes, a tree will develop double leaders known as codominant stems. Codominant stems can lead to structural weaknesses, so it is best to remove or shorten one of the stems while the tree is young.
A tree’s secondary branches contribute to the development of a sturdy, well-tapered trunk. When numerous branches are being removed, it is preferable to retain some, at least temporarily, to promote trunk diameter growth.
Permanent branch selection to prune
Most of the branches present on a young tree at planting will be pruned away at maturity to provide clearance for mowing, pedestrians, and/or vehicle traffic.
The height of the lowest permanent branch is determined by the tree’s intended function and location in the landscape.
The road side of a street tree may be raised to 4.5 m to accommodate traffic. In most other situations, 2.5 m of clearance is sufficient.
Trees used as screens or wind breaks, however, usually branch low to the ground. Sufficient branch spacing and balance, both vertically and radially, is important.
The space between permanent branches should be approximately 3 percent of the tree’s eventual height 0.5 m for a tree that can grow to be 15 m tall. Beyond spacing, the strength of branch structure depends on the relative size of the branches and branch angles.
Branches similar in diameter to the trunk or limb from which they arise are more prone to failure than those smaller in diameter.
Narrow angles of attachment or tight crotching can enclose bark within a branch union. Such growth is called included bark, a condition that weakens the branch attachment and may lead to failure when the tree matures.
Branches with weak attachments should be pruned while still small. Balance should be considered by retaining some branches in each direction radially, spreading from the centre outward. Make sure one scaffold branch is not allowed to grow directly above another.
When pruning, be sure not to remove too many branches. Leaves and their supporting branches are major sites of food production and storage. Eliminating too much of the canopy can “starve” the tree, reduce growth, and increase stress. No more than 25 percent of the crown should be removed in one pruning.
Newly planted trees how to prune
Pruning of newly planted trees should be limited to the removal of dead or broken branches. All other pruning should be withheld until the second or third year, when a tree has recovered from the stress of transplanting.
Don’t forget to prune and wound dressings
Despite any claims otherwise, research has shown that wood dressings do not reduce decay or speed wound closure and rarely prevent insect or disease infestations. Most experts recommend that wound dressing not be used.
