Winter is the best season for doing necessary pruning of fruit trees for optimum production and good quality fruit. This not only will improve yield but also is proper management to limit or even eliminate diseases and pests, without resorting to petrochemical sprays. It is not to say that you should not do light pruning throughout the year when necessary, for instance, pruning waterspout branches that do nothing to add to yield but actually suck nutrients needed for production of fruit producing branches.
Many people look on pruning as the most daunting task in the orchard, but it is simple once you observe some key pruning essentials. First, as stated above, winter dormancy is the best time for major pruning not only because pests and disease are also largely dormant, but also because the nutrient rich sap is stored deep in the root system. This will limit the chance of “bleeding” of sap that is not only unsightly but can attract insect pests later on in the season. The best time for winter dormancy is generally January and early February. If you get later into February you risk running into the days of below freezing nights and above freezing days, most especially in the upper 40⁰ F. range. This induces sap flow, which is what maple sugaring folks look forward to but can be detrimental to the fruit orchard. Overall, it is best to start with the largest branches first; this will dictate which pruning implement to use. Saws and chainsaws are best for branches exceeding 2 inches; long handle lopping shears are best for branches under 2 inches; and, hand shears are best for shoots and smaller branches … warning some people use anvil pruners, these are the ones that have a blade on one side and a flat surface which impacts the blade when cutting. These tend to compress the branches, wounding and causing later die-back of the branch. It is best to use by-pass loppers and pruning shears which are designed so the blade and the opposing element by-pass each other during cutting. This makes for a cleaner cut limiting damage to the remaining cut branch. Below you will find a few generally regarded basic guidelines that should add to your harvests and also reduce incidence of disease.
Pruning Rule #1: Cut out overlapping and crossing branches look especially for shoots that have the potential to cross and overlap during the upcoming productive season. Also cut out all larger waterspouts. Waterspouts are the unproductive branches that get long and leggy and produce no fruit. These can usually be recognized by their characteristic habit of growing straight up at 90⁰ angles to their parent branch. This is not to say that all straight vertical 90⁰ branches are waterspouts, but likely are so: discretion and experience is needed here to separate the two types of branches. When trimming limbs, always trim to 1 or 2 smaller shoots branching from it. This will provide for potentially productive branches to take the place of the lost limb. Warning: do not cut branches flat against the parent branch, only to the growth rings just outside the parent branch. Leaving the growth rings intact will insure proper healing over of the branch.
Pruning Rule #2: Cut out all wood that is broken, diseased, or dying. When pruning diseased or dying branches, cut well below the obviously diseased wood into healthy wood; identify diseased and dying wood by:
o Darker or different color wood;
o Sunken or puckering bark;
o Swollen and discolored ring around the diseased area somewhat like an infection in animal tissue.
Pruning Rule #3: Keep the tree balanced. Step back frequently and far enough that you get an overall perspective of the tree from all angles. If this is not done correctly it can result in uneven distribution of the fruit causing the tree to lean in the direction of the abundance; this could have both short term and long term effects on the tree, including splitting of the trunk.
Pruning Rule #4: Depending on the fruit, learn the three cuts needed for the particular fruit tree you are working on:
o Vase cut, is where three to four limbs of the trunk are retained and allowed to grow in different directions. The space between these is left open to help flow of air and sunlight to the interior. This is a good cut for apples and even pear trees as it allows the interior leaves to receive adequate light for photosynthesis during full leaf out.
o Central leader cut, is where a strong and vibrant central stem is allowed to grow with branching off of it. This is generally of benefit to cherries, both sweet and sour, and can be used for stone fruits like peaches, plums, and apricots.
o Modified central leader cut, is similar to the preceding central leader cut but allows for two vibrant branches. This can be used as an alternative to the previous cut.
o There is also a heading-in, aka, pinching-off cut which encourages lateral growth usually without losing the vertical leader concentration of growth hormone which the tree produces. Keep in mind when making these or any other cuts to a bud leave about 1/8 to ¼ inch. This will protect the delicate buds from being knocked off by two or four legged animals when they brush against them.
I prefer using a vase cut for all my fruit trees because I’m surrounded by a deep forest and our seasons are generally quite humid. Both of these conditions promote fungal disease so keeping a vase shape allows freer flow of air thus aiding in preventing fungus.
Pruning Rule #5: I reiterate make the cuts as clean as possible, this not only means no frayed edges, but also cleaning your tools in alcohol before proceeding onto another tree. Your tools also should be sharpened regularly to achieve the finest edge this will insure a clean cut. If you managed to mangle a cut, go back if possible and trim lower achieving a clean cut.
Pruning Rule #6: Do not, I repeat, do not use pruning paints or other sealers on your cuts. This was once recommended especially when cutting major limbs but while intended to seal out pests and disease it also has the effect of sealing in these same problems.
Pruning Tip: Peach tress produce fruit on the current seasons wood, that is, new wood. So with peaches prune back severely all 2 year growth. This will allow as much fruit producing wood to grow as possible.
Books have been written on pruning alone. Depending not only on the fruit but also whether standard, semi-dwarf, or dwarf pruning, shaping, and cutting can be different. It is best to get a good book and learn from it.
In closing, pruning is not some esoteric technique of an elite orchardist. It can be done by everyone and don’t let your inexperience scare you, there is almost nothing you can do in pruning which can be undone either immediately or over one or two years. Short of cutting down the main trunk, or girdling it, pruning is a very forgiving tool to improve your harvests. Let me finally say, the window of opportunity for pruning, as in most garden maintenance, is limited. In the case of pruning we are talking about a 6 or 7 week period, 8 at most, between January and February. This can be further shortened by inclement weather. This in not to say that late December is not a good time, at this time we are usually too busy with the Christmas holidays to bother with it. Therefore, take advantage of the dormancy as long as it lasts, because if the opportunity passes without tending to this much needed chore it will have an impact on your fruit production, quality, and harvest. So as the old-time motivational poster used to say: DO IT NOW!
Richard of Danbury, D.S.G.