There are three main types of crown pruning techniques that are used to adjust the size of your tree's leafy canopy. Know what they achieve and when to use them so that you can better manage your landscaped trees.
Sometimes the crown of a tree is simply too low. The low branches may block sidewalks, rub against roofing shingles, or make it difficult to mow and tend to the landscaping beneath the tree. Fortunately, proper trimming techniques can be used to lift the crown so that the lowest branches aren't causing problems anymore.
The method is relatively simple. The lower tier of branches on the trunk are cut off. Cuts are made flush to the trunk so that the wounds can heal over quickly and easily. If the crown must be lifted quite a bit, your tree service may recommend slowly trimming up by one level a year over several years. This will allow the tree a chance to put on additional growth in the top part of the crown and maintain balance.
Reducing the height of a tree is the most challenging form of crown pruning and should only be done as a last resort when the only other option would be to remove an overly tall tree. Reduction is most often necessary when the height is posing a safety hazard, such as when trees grow under power lines.
The main key for successful reduction is to avoid topping the tree, which is a technique that cuts the top flat at the desired height. This method is ugly and can negatively impact tree health. The better method is to gradually reduce the length of all the branches by about 1/4 their current length. Repeat this reduction each year over two or three years until the crown is reduced to the desired size.
A tree with a lot of branches and dense foliage in the crown may not get sufficient sunlight or air circulation. This creates an environment where the foliage may grow in sparsely and fungal diseases will thrive. Dense crowns are mainly an issue with deciduous and broadleaf trees as conifers tend to only produce dense foliage at branch tips.
Thinning is a pruning technique that reduces the density in the crown. Your tree service will selectively remove some branches, particularly those that are rubbing together or that have poor growth form. The trimming is done to open up the crown so more sun and air can make their way through. Care is taken to maintain balance in the crown throughout the thinning process.
Contact a tree trimming service for more assistance.