The Peach Pruning Blueprint

- [Narrator] Peach trees are pruned to maintain tree size and shape and to help manage light and crop load.

The lack of suitable dwarfing rootstocks limits the extent of orchard intensification.

However, with judicious pruning, standard trees can be maintained at a height of seven or eight feet.

The natural tree form of a standard type peach tree is a vase shape making it easy to train trees to an open center system with three or four primary scaffold branches.

A modification of the vase is a V shape with two to four scaffold branches.

This more uniform architecture is adaptable to tighter in row tree spacings, which can result in improved yields for the first several years and increased opportunities for mechanization.

Leaves intercept light and the biochemical reaction, called photosynthesis, light energy is used to produce carbohydrates that are used for growth of all parts of the tree.

Light penetrates only about three or four feet into the tree canopy.

The fruiting zone of an open center tree can be thought of as a doughnut supported by scaffold branches.

The ring shaped fruiting zone is about four feet wide and four feet deep.

If light becomes limited, the fruiting zone will move higher above the ground with little fruiting in the lower portion of the tree.

Both dormant and summer pruning are used to maintain optimum light conditions within a tree canopy.

Dormant pruning is used to remove upright and vigorous shoots that shade the tree interior to limit the size of the tree and to remove excess fruiting shoots.

Pruning temporarily reduces a tree's tolerance to low temperatures.

Therefore, avoid pruning before late February and before predicted low temperatures.

Summer pruning is performed on newly planted trees to select scaffold branches on trees and to direct the growth of young scaffold branches.

For fruiting aged trees, removing upright and vigorous shoots in June and July will reduce shading to maintain fruiting wood in the canopy interior.

Pruning is also a tool for managing crop load.

The number of fruit per acre is more critical for fruit size than the distance between fruit.

The optimum number of fruit per acre depends on the cultivar and availability of irrigation.

For cultivars that tend to produce small fruit, an acre will support about 45,000 fruit, which would require 11,250 shoots if the fruit are thin to four fruit per shoot.

For cultivars with medium fruit size, a reasonable target crop load is 70,000 fruit on 17,500 shoots per acre.

For large fruited cultivars, the target is 100,000 fruit on 25,000 shoots per acre.

To calculate the desired number of shoots per tree, simply divide the desired number of shoots by the number of trees per acre.

For example, for large fruited cultivars with tree density of 150 trees per acre, retain 167 shoots per tree, and four fruit per shoot to produce 100,200 fruit per acre.

Pruning practices will vary somewhat depending on the specific objectives of individual peach producers.

But the following guidelines can be used to develop low spreading, open centered trees.

The height of the scaffold limbs above the ground depends on the height of the initial heading cut made at planting.

Pruning peach trees at planting also balances the treetop with the small root system and induces branching on the trunk.

Larger trees usually arrive from the nursery as branched whips.

The side branches are often weak and should be pruned to two to three buds with the goal of having shoots suitable for major scaffold limbs developed from the stubs.

If the branches happen to be strong with wide crotch angles, they can be retained as scaffold limbs and be pruned to six or seven buds.

Smaller trees with no side branches should be headed at 24 to 30 inches above ground.

Trees should be pruned at least once and possibly two times during the first summer before growth ceases.

Summer pruning reduces the amount of dormant pruning required and will direct growth into the desirable scaffold branches.

In late May and again in July, remove low shoots on the trunk to a height of 20 inches.

Remove all shoots forming angles less than 45 degrees with the trunk and all vertical shoots that are unacceptable as scaffold branches.

Encourage a spreading growth habit by pinching or pruning upright growing shoots back to an outward growing secondary shoot.

This should be done in late June or July when shoots are actively growing.

Another approach to pruning first year trees involves retaining the top few shoots with four crotches and heading them in half in late June.

Growth of the headed shoots is suppressed while encouraging growth of the lower shoots that have wide crotches.

The small bush in the tree center is removed during the winter to leave the lower wide angled branches.

If trees are pruned during their first summer, very little pruning will be required their first winter.

The pruned tree should begin to resemble an open vase.

Remove root suckers, downward growing shoots and strong vertical shoots that shade the tree's center.

Keep the tree balanced by shortening the longest branches.

Pruning trees during the second summer improves light penetration into the tree's center and develops fruiting wood for the third season.

Summer pruning should be completed by mid July.

Peach trees that have grown well for two years will have numerous flower buds and if pruned moderately, may produce 20 to 40 pounds of fruit during the third summer.

Encourage early fruiting by retaining as much of the tree as possible including the smaller side shoots growing from the selected main branches.

Head the scaffold limbs above an outward growing secondary shoot to encourage a spreading growth habit.

Young fruiting trees usually grow fairly vigorously and moderate corrective pruning is needed to keep their centers open and maintain the desired tree size.

Continue annual summer pruning to eliminate vertical watersprouts and to tip upright scaffold limbs to outward growing secondary shoots.

Do not remove all fruiting shoots in the center of the tree as the most productive open center trees have fruiting wood throughout the tree canopy.

By the 6th year, the canopy should be fully developed from maximum yields.

The objective of pruning peach trees during year six and beyond is to maintain productive fruiting wood throughout the tree.

Prune each year to keep the tree within bounds and to prevent the branches from breaking.

Thin out fruiting shoots to a spacing of about four to six inches apart along the limbs to stimulate better growth of remaining shoots to prevent excess fruiting and fruit thinning and to improve fruit size.

Also remove fruiting shoots that are less than six or greater than 18 inches long.

Shoots that are 12 to 18 inches produce the largest fruit.

A thorough pruning job requires time and labor, but it also saves time in labor during thinning and harvest.

Peach trees that are trained and pruned properly are capable of producing high yields of good quality fruit for 15 to 20 years.

The only way to maintain productive trees that are less than 10 feet tall is to prune the trees every winter and summer.

Proper pruning also facilitates fruit thinning and more open canopies with less disease and insect pressure.

For more information on establishing and training orchards, visit the Penn State extension, Tree Fruit Production website.

If growing trees is a new venture for you, gather as much information as possible prior to planning a new orchard.

And also consider taking a Penn State extension workshop on commercial fruit growing.