Big picture on pruning

Pruning Fruit Trees

Garden literature is full of pruning information, but beginners can easily be overwhelmed. The most important thing is to understand how the tree grows and the benefits of making a cut. Observe the tree's natural growth habit. What will its form be when it matures? Start slowly; always have a good reason before making any cut.

Pruning is said to be “what man does in his efforts to grow plants the way he wants them.” Yet nature prunes ruthlessly using shade, wind, fruit overload, ice and snow. These natural operations often destroy the tree, allowing decay to enter. Human efforts can enhance beauty, form, and fruit production, strengthen structure, and prevent wounds and disease, ultimately extending the tree's health and life.

Proper pruning shapes the tree to allow good sun exposure. This encourages optimal photosynthesis. Sunlight actually strengthens the fruiting wood; shading inhibits growth.

The “open center” and “central leader” systems are two pruning methods the gardener can choose.

“Open center” is designed to produce a smaller tree. The fruit can be harvested without a ladder and pruning is done from the ground. Three to four strong scaffold (or main structural) branches are chosen, evenly distributed around the trunk. The total height is below 6 feet. This creates a more open tree, increasing fruit quality by allowing greater light penetration and air circulation, which discourages disease and insects.

“Central leader” produces a taller tree, allowing a larger harvest and more shade. A central branch becomes dominant, and the lower scaffolding branches are chosen to grow evenly below and around the leader.

Once the system is decided upon, pruning should be done in February or March after severe winter weather is over. Never prune on a wet day as fungal disease spores are spread by water. Tools should be sharp, of high quality, so that cuts will be clean (not tearing the wood jaggedly). See below for first and second year pruning.

You may be asking which branches to cut first. The easiest way to see the tree's framework is in the winter without the leaves. First cut branches that are broken, dead or diseased. Branches growing straight down, straight up or directly into another branch can also be removed. If there are suckers around the bottom of the trunk, remove them. Remove small branches before larger branches are selected. Next, choose the structure or scaffolding branches, usually 3 or 4, to be evenly distributed around the trunk. Pruning during the first 4-5 years establishes framework and is called training.

Cuts made at the main trunk are called thinning. The branch should be removed just above the wrinkled “shoulder” where it attaches, making the smallest cut possible. Wounds left after the cut should not be covered with ointment or paint. Natural drying seals the tree from infection.

Cuts, made at a lateral outward-facing bud, are called heading back, and encourage growth in a specific direction. Each bud allowed to remain will swell into growth, ultimately becoming a branch. This determines which way growth proceeds. It is important to cut just above the bud, leaving only ¼ inch. Otherwise, a dead stub will develop which is unsightly and may allow entrance of disease.

Pruning is essential for quality fruit. Sun exposed wood produces the best fruit. Some fruit is produced on longer-lived spurs or branches. This influences whether pruning should be light or heavy. Cherry, European plum and pear trees bear on long- lived spurs, so retain most spurs for fruiting. They should be lightly pruned which means removing approximately 20% of the branches. Apple trees can be pruned a bit more. Apricot, peaches, nectarine, fig and Japanese plum bear on one-year growth, so pruning can be heavier, up to 50%. If a tree lacks vigor, it should be heavily pruned while dormant to encourage new growth. If a tree is overly vigorous, pruning can be done in the summer in addition to winter to reduce the volume of leaf growth.

Resist the urge to spray pesticides on your fruit trees since beneficial insects will be destroyed before pollination can occur. Bees are an integral part of the life cycle of flower to fruit. Now is the time to spray the entire tree with dormant oil to suffocate over-wintering pests, but don't spray when temperatures are below 40 degrees

Pruning one and two year trees

To prune a one year old apple tree with a modified central leader, follow these steps:

• Select a strong, upright central leader that will become the main trunk of the tree.

• Cut off any competing shoots or branches that are growing near the base of the tree.

• Thin out any shoots that are growing along the central leader, leaving only a few of the strongest and most evenly spaced shoots.

• Cut back the remaining shoots to about 4-6 inches in length, leaving a few buds on each shoot.

• Select 2-3 shoots from near the top of the tree to become the future scaffold branches.

• Cut back these scaffold branches to about 18-24 inches in length, leaving a few buds on each branch.

Repeat this process every year, removing any shoots that grow from the base of the tree and cutting back the scaffold branches to maintain their spacing.

This method will help guide the growth of the tree into a well-structured form with a strong central leader and evenly spaced scaffold branches, promoting good light penetration and fruit production.