Fruit Tree Pruning

Fruit Tree Pruning

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Seeing a notice about a pruning demonstration at a local nursery, I stopped by to learn the what, why and how of fruit tree pruning. I had no idea that there is an art and science to pruning. When I saw a Master Gardener, who was making the presentation, take a beautiful-looking tree and reduce it to a vertical stick, I was sure that I had just witnessed a crime. Little did I know that, due to my lack of knowledge, it was I who was committing injustice to my own trees.

It is important that you know why you are pruning - your objective should be very clear. It was not a crime that I had witnessed when I viewed the initial demonstration. I just did not understand the objective.

The principal objectives of fruit-tree pruning are:
• to direct or control growth, shape and size
• to stimulate new fruiting wood and encourage flower and fruit production
• to remove broken, damaged and diseased wood
• to space the new fruiting wood to allow good air circulation and sunlight penetration into the canopy.

Prune annually in late winter or early spring (late dormant period) for fruit production and some tree shaping. (Note: apricots should be pruned six weeks before rain is expected or after the rainy season has ended to prevent water-borne disease.) Prune in spring to summer to control growth, do some shaping, and help thin fruit.

There are three pruning phases in the life of a deciduous fruit tree:

The first pruning phase occurs at planting, when the first cut should be made to foster development of a vase-shaped structure. After a bare root tree is planted, the trunk should be "headed back" at 24 - 32 inches above the soil surface. This most important cut serves to establish low origination points of structural branches which will allow most pruning, harvesting and pest management to be performed without a ladder during the life of the tree.

The second phase of pruning begins in the second year after planting and serves to establish tree structure. The initial low heading cut results in several branches growing outward at various directions and angles. Three or four strong upwardly-growing branches, spaced at intervals around the trunk, should be selected as main branches (scaffold). Additional branches should be removed. Pruning in the next few years should concentrate on structural development of these main branches and well-spaced secondary branches (laterals).

The third phase of pruning begins with the onset of maturity, which is 5 to7 years for most fruit trees. Pruning at this stage serves to invigorate and direct the growth of the tree with a goal of keeping it producing new, fruiting wood. In home orchards, peaches should be pruned the most severely and cherries the least.

There are important differences between each type of fruit tree. For example, peaches bear fruit on terminal wood of the previous season. Therefore, well-spaced lateral shoots with flower buds are retained. It is common to thin (remove) half to two-thirds of peach laterals and to shorten (head) remaining fruiting wood. Apricots, plums and cherries bear fruit laterally on spurs which live three, five, and ten years, respectively.

Next week's column will cover pruning overgrown, large, neglected fruit trees. There will be a live demonstration of fruit tree pruning on February 2, 2013, at the Tuolumne County Master Gardener demonstration garden located behind Cassina High School, 251 South Baretta Street, Sonora. Hours are from 10:00 am to 1:00 pm.

This article adapted from University of California Cooperative Extension (UCCE) Kern County "Planting and Early Care of Deciduous Fruit Trees" and former UCCE Tuolumne County Master Gardener Gary Fowler. Jim Gormely is a 2012 graduate of the UCCE Tuolumne County Master Gardener program.