Fruit Trees

1. Q. I have set out a large number of fruit trees and they don't seem to be growing. Some of the trees have been out 2 years. I have never tried to grow fruit trees before and really don't know how to care for them. How can I encourage them to grow?

A. The reason your young fruit trees have not grown may be poor soil conditions such as heavy clay, rocky soil, low levels of fertility, etc. Often it is poor weed control or trees which froze or dried out at the nursery. Adequate moisture is also critical for growth. However, fertilizer is not always the key.

To get your fruit trees to grow, I would suggest the following:

  • Be sure that the trees receive adequate moisture during the growing season.
  • Apply a 3-inch thick layer of mulch around each tree to cover the soil over the root system.

Avoid growing grass around the tree for several years until it is well established. Proper pruning and training is important to shape the growing trees. Pruning at planting encourages the vigorous growth of numerous scaffold branches. This will allow greater shaping flexibility as the trees grow. Pruning is a dwarfing process though, so only prune if your trees are growing and you have a reason to prune.

1. Q. I recently read about the espalier method of growing fruit trees. Can you tell me more about this?

A. The art of espalier, originated in France and Italy about 400 years ago as a method of training fruit trees in a flat plane usually in a symmetrical form against a wall. There are many different systems. Some are quite elaborate, requiring considerable time and patience as well as detailed knowledge of the plant's growth characteristics. The easiest espalier system is the horizontal cordon. Apples, pears, and plums adapt well to this system. The trees are usually supported by a wall, a fence, or a wire trellis. Training to the four-tier cordon or four-wire trellis is relatively easy.

An espalier system can provide an effective way of producing a large volume of high quality fruit in a limited area. Trees trained in this fashion should be on dwarfing rootstock, otherwise, they tend to grow too large and are difficult to hold within bounds.

A simple four-wire trellis may be constructed by setting 8' posts 2' in the ground, spacing them 12' apart, and running wires through the posts at heights of 18, 36, 54, and 72 inches. Plant two trees of the desired variety 6' apart between each two posts. Cut the trees off at about 18 inches.

Usually three or more shoots will develop near the point of the cut. Retain the uppermost shoot and develop it as the central leader. The other two can be developed into main scaffold branches to be trained along the lower wire, one on each side of the central stem. Remove all other growth.

The two shoots selected for scaffold limbs should be loosely tied to the wire as soon as they are ten to twelve inches long. Twine, plastic chainlink ties, or other suitable material may be used. Tie the shoots so that they are nearly horizontal. This reduces vegetative vigor and induces flower bud formation. However, if the end of the shoot is tied below the horizontal, new growth at the end will stop and vigorous shoots will develop along the upper side. At the end of the first season, the lateral branches on the lower wire should be established and the central leader should have grown above the second wire.

During the dormant pruning at the end of the first winter, cut the central leader off at a bud just below the second wire. Repeat the process of the previous spring by developing two scaffold branches to tie to the second wire and allow the central leader to grow above the third wire.

This process is repeated during the next two seasons, at which time a total of eight scaffolds, four on each side of the tree, should be firmly established.

By the end of the fourth season, the trees should be in heavy fruit production. All pruning is then done during the spring and summer months. After new growth in the spring is about two inches long, cut it off and also remove about one-fourth of the previous season's growth. Terminals of the scaffold are left untouched.

About the first of August or as soon as new growth reaches ten to twelve inches in length, tip prune the shoots to prevent vigorous growth from getting out of bounds.

3. Q. What are spurs?

A. Spurs are short, stubby, side stems that arise from the main stem on wood that is usually in its second year of growth. The fruit of apples and pears is borne on spurs. Grapes can also be pruned back to short spurs.

4. Q. What is dormant oil? What pests will it control on apples and pears? How does dormant oil spray kill insects, and when should it be applied to fruit trees?

A. Dormant oil is a highly refined petroleum oil used primarily to control scale insects and the overwintering eggs of red spider mites and aphids. It is diluted with water prior to spraying. The oil coating suffocates these pests as well as their eggs. Insects cannot become resistant to it.

Dormant oil should be applied to fruit trees in early spring while they are dormant but just prior to bud swell. A dormant oil spray one week before bud break is most effective. The entire tree should be covered with a layer of the oil.

5. Q. Is root-feeding fruit trees preferred over scattering fertilizer on the surface of the ground?

A. Fertilizer scattered evenly over the surface of the ground above the root system is just as effective for plant maintenance as is root feeding. Scatter the fertilizer starting about six inches away from the base of

shrubs or about 1 foot from the trunk of a tree and extending to a short distance beyond the ends of the branches. The fertilizer can be lightly raked or scratched into the mulch or soil and then watered in.

6. Q. When should I prune and fertilize fruit trees?

A. Prune fruit trees any time during January - March before flowering begins. Trees can be pruned after budbreak with no harm to the tree if you happen to be late in getting started. Fertilization should occur immediately before bloom or leaf sprout occurs which is usually in March. A good general recommendation for rate to use per tree is one pound of fertilizer per inch trunk diameter. Use 21-0-0 or ammonium sulfate if your soil pH is above 7.0. A complete fertilizer such as 15-5-10 can be used if your soil pH is below 7.0 If additional applications are made, use only nitrogen fertilizer. Trees should make 18-24-36" of terminal growth annually.

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