Maureen Sexsmith-West ISA Certified Arborist PR-4600A Apple trees – it’s a love hate relationship. In the spring we love the beautiful floral display and the chirping of birds. By late summer you are preparing to rent a bobcat and dump truck to contend with the fruit which is littering your lawn, you are on your 8th container of wasp repellent and the fermenting fruit makes your yard smell like a brewery. It doesn’t need to be this way. We’ll take our lead from orchard producers on this one – they don’t waste one apple.
Apples are vigorous growers and should be pruned annually to manage the delicate balance between plant health, foliar production, sun exposure, fruit production and root development. Training, pruning and good cultural practices go hand in hand. Early efforts to create good scaffold branch structure will result in reduced insect and disease problems, consistent crops and stronger wood to support the weight it will need to bear. A few well positioned annual pruning cuts are less stressful to the tree and considerably less expensive than addressing a tree that has been left untouched for 3-5 years. Most cuts should only require a pair of loppers, secateurs and a hand saw. Chances are that by year 4, you are ready to have it removed out of frustration or go into shock when someone presents you with an estimate to prune it properly because they have to bring out the chainsaw and chipper. In our region – major pruning should be done in February and March when the tree is still dormant. Since the worst of cold winter temperatures has generally passed, waiting until this time helps minimize frost damage to open cuts. It is also more pleasant to work out of doors. It gives you the opportunity to see the structure of your tree without the distraction of leaves. You can easily identify crossing and rubbing branches, dead or diseased branches, water sprouts, reverted growth, branch spacing and branch unions. Branch unions should have a visible bark ridge – this means it is well attached and can bear considerable weight. Remove branches that do not have this mini mountain range as soon as possible to avoid failure later on.
Scaffolds branches (permanent larger branches) should be identified. Leaving on ‘temporary’ smaller branches will help increase wood strength and provide leaves for photosynthesis as the tree matures. The first permanent scaffold should be around 30 inches (75 cm) above the ground, with each addition scaffold separated by 8 inches (the length of your hand) in different locations around the trunk. This makes it easier to pick as well since you can access each branch easily. Consider the room you will need for maintenance of turf or other ground covers below your tree. If it is mulched, you may be able to have branches lower on the trunk.
Removing more than 25% of the tree’s biomass in one season will result in a panic response to replace its food production factory (leaves). Trees are NOT hedges and should be PRUNED not shaped/trimmed. All cuts should be made at a branch/twig union just outside the branch collar. This allows the tree to compartmentalize and create callus wood around the wound (which looks like a donut) until it has completely hidden the cut.
Topping cuts (those made randomly between twigs and branches shown here) is highly discouraged as it will result in a ‘porcupine’ of weakly attached vertical water sprouts, and a deeply shaded canopy of unproductive twigs. Re-growth is vigorous and before you know it, your tree is taller than before. Twig die-back from the ‘stub’ is inevitable since the tree has no chemical messages to compartmentalize at mid-point cuts. Diseases can attack the unprotected pruning sites. Watersprouts are inevitable. This means making hundreds of smaller cuts next time and who has the time or money to deal with this when it can be avoided?
Once the fruit has set on the branches, remove any vigorous vertical tip growth or upright sprouts as this will detract from fruit production (10% maximum). You can also thin your crop (just like thinning rows of carrots) by picking marble sized fruit instead of waiting until it is fully developed. Water appropriately from early spring to freeze up and respond to insect feeding, eliminate egg sacks and prune out any early indications of wilting or dying twigs to control fire blight (don’t forget to sterilize tools between cuts in the active growing season).