Pruning for Fruit Production

Pruning fruit trees is an essential part of tree health and the production of quality fruit. A healthy tree is better able to resist the damage done by drought, weather, insects and disease. Pruning also helps to develop structure that enables the tree to bear the weight of a heavy crop, as well as to set fruit. Some trees tend to bear in alternate years; this too, can be alleviated with careful pruning.

  So when is the best time to prune? Just about any time is OK, but sometimes are better than others. The best time for most fruit trees is when the tree is completely dormant. In some cases, such as peach or nectarine, it is better to wait until the coldest weather has passed, as cut ends can be damaged by a sudden cold snap. Judicious summer pruning can promote even ripening of fruit and at the same time, have some dwarfing effect.

  Begin with sharp, clean tools. For a clean cut, any loppers or clippers you are using should be the by-pass type. This means that the cutting blade will pass beside the support blade, unlike the anvil type, on which the cutting blade presses against the other. Your saw should have a narrow enough blade to get into narrow crotches easily, for a good, clean cut. A good disinfectant for your tools is one part Clorox in nine parts water. Use this between trees or after cutting away diseased limbs.

  The most important thing to know is, where to start and when to stop. This means knowing which part of the tree bears fruit and how much fruit the limbs will support. This is not as simple as it seems. For example, peaches come from the “fuzzy” buds on last summer’s growth and will bear fruit only once. Most other stone fruit bear on the two to four year old growth, for as many years. On an apple or pear, it will take a leaf bud several years to develop into a fruit bud that may bear for many years.

  For general pruning, the first thing is to remove crossed, damaged, dead or diseased limbs. Be sure to cut limbs next to the growth ring (low ridge at base of limb), leaving no stub. The next thing to do is to thin limbs, allowing for room to grow and for fruit to hang unobstructed. This is a good point at which to step back and visually assess the balance and length of limbs. When making these adjustments, cut back to a branch, twig or bud. Bear in mind, that you are influencing the direction of new growth. This general type of pruning is all the pruning that is needed to keep your trees healthy and happy. If you are taking on a severely overgrown tree, easy does it. Removing more than one third of the tree in one pruning, can have harmful effects. As an old tree trimmer buddy of mine once said, “You can’t make a tree out of it overnight, save some for next year.”

  After the general pruning, one can further improve crop production by detail pruning. Detail pruning varies by type of fruit (apple or peach) and in some cases by the variety (Pippin or Red Delicious).

  I generally prefer to prune most of my fruit trees from around mid-January to around mid-February. I also like to apply a paraffin based dormant oil spray at that time. The oil spray is non-toxic, killing most of the insects and their eggs by suffocation. Remember, when using any type of spray on your trees, read the entire label carefully and use appropriate personal protective equipment.

  For more information on this, any other garden subject, or to get on the workshop mailing list, contact the Greenlee County Cooperative Extension office at 359-2261 or email Bill Cook at wrc@email.arizona.edu