Generally speaking there are three things which will guide your decision about the right time to prune your tree. These are: the type of tree, the age of the tree and what you’re trying to achieve with your pruning. Sometimes however there’s one factor that overrides all of these considerations. If a large tree is clearly unstable and there’s a risk of falling branches causing damage, the time to prune is as soon as possible. Of course you want to care for your trees, but if they’re dangerous you need to take prompt action. If the tree or branches concerned are large enough to pose a danger if they fall, you may also need to question if you have the tools and experience to deal with it safely. If not you’d do better to call in a professional tree surgeon.
How the Type of Tree Affects your Decisions
Most trees are best pruned during their dormant season, autumn or early winter, but there are some exceptions to this. Maple, horse chestnut, birch, magnolias and walnuts are better pruned in late summer, as healing is quicker and some of these species ‘bleed’ if pruned in winter. Trees which are vulnerable to silver leaf disease, such as cherry benefit from summer pruning, as the spores that cause the disease are not present in the air. For the same reason the best time for pruning plum trees is in full summer. Pruning in late winter (after Christmas) can cause many trees to bleed sap, this is not usually fatal to the tree, but it can weaken it and it doesn’t look very nice.
Pruning Young Trees
In order to encourage the development of an attractively shaped and well balanced specimen, younger trees generally need harder pruning than more mature specimens. It can feel a little frustrating, almost as fast as the tree puts on growth you cut it off again! When you’re pruning fruit trees in the summer this will also mean that you’re taking off branches that have fruit on them. You might be tempted to under-prune but it’s better to have a healthy tree that will give you fruit for many years to come than a heavier crop in the early years. It may help to remind yourself that most fruit trees will produce far more than you can use, but if you can’t bring yourself to be hard enough on your younger trees find a tree pruning London firm to do it for you!
What Do You Want to Achieve from your Tree Pruning
The usual reason for tree pruning is to make the tree smaller but some pruning techniques will actually encourage thicker, bushier growth. Two techniques that have this effect are coppicing and pollarding, cutting trees either to within 12 inches of the ground (coppice) or to the trunk (pollard). Not all trees will respond well to these techniques and they’re not generally used in residential gardens. However dogwoods can be pollarded, or more usually coppiced to encourage plenty of attractive red stems for winter interest. This is usually done in February or March.
There are three major techniques used to accommodate trees to the space and situation available to them.
This technique doesn’t actually reduce the overall size of the tree but will give a more even display of foliage. Thinning will allow more light to pass through the tree and also reduce wind resistance. A skilled tree pruner will work systematically through the whole of the tree to give a pleasing, symmetrical effect and will never reduce the overall volume by more than 30%.
Crown Lifting (sometimes called crown raising)
Pruning a tree so that branches start spreading from a higher point up the trunk than they otherwise would. This will increase the light in the area under the tree and increase the clearance under the canopy. In older trees the technique should be restricted to secondary or tertiary branches, not those growing directly from the trunk. The wounds left by removing large branches directly from the trunks can easily lead to extensive decay and undermine the whole stability and health of the tree. No more than 15% of the tree crown should be removed and after crown lifting the crown should still form at least two thirds of the overall height of the tree.
This technique is the one that makes the tree smaller in overall stature. The result should be similar in shape to the original tree but take up less space. In the case of a tree that is vastly oversized for the space available, reduction may need to be done over several years to avoid over-stressing the tree. Not all trees are suitable for reduction, any tree surgeon you’re considering using for your tree pruning in London should be able to tell you what is or is not achievable in any given instance.
Reductions, thinning and lifting are usually best done in the dormant season when the shape of the tree can be most easily assessed, though it the species is more suited to summer pruning this will be a more important consideration.
Some General Considerations for Mature Trees
Any tree pruning should start with the removal of dead or diseased branches, something that can be done at any time of year, and then proceed to those which are crossed or will cross in the near future. It often happens that by the time these tasks are done the tree needs no further pruning.With mature trees it’s always better to remove too little rather than too much at one time. Tree pruning is an effective technique, but there’s only so much that can be achieved. If the former owner of your property has planted a species or variety that’s simply too big for the space available there may come a point when it’s better to remove it and replace it with one that will suit.