Pruning         

By John Fulton

[MARCH 7, 2006]  With the calendar pointing to spring, it's time to think about finishing up pruning chores. It doesn't seem possible that we need to be gearing up for the outdoor season. But it is time, and one of the first items of business is pruning.

Let me start by saying that pruning is an art rather than a science. There are some basic rules of pruning that should be followed, and the rest is more personal taste than scientific fact.

Starting with the proper tools, you should have bypass hand shears, for cutting twigs up to one-fourth inch; bypass loppers, for those in-between cuttings of one-fourth inch to 1 1/4 inch; and a good pruning saw for larger limbs. Bypass, rather than anvil-type pruners are recommended.

Next, the general rules that should be followed:

1. Remove dead and broken branches.
2. Remove diseased branches or diseased parts of branches.
3. Remove water sprouts -- rapidly growing young shoots that grow straight up.
4. Remove suckers, which grow from roots or at ground level.
5. Eliminate competition between branches.
6. Eliminate V-branching, where two branches of similar size form a narrow V.
7. Remove weak, slow-growing, drooping, nonproductive branches.
8. Remove branches, or parts of branches, that touch the ground.
9. Avoid selecting main branches that grow toward the direction of prevailing summer winds (southwest in our case).
10. Particularly with fruit trees, do training-only pruning for the first five years. Severe pruning early on will tend to delay fruit onset.

Now that we have the rules, we need to know when to do pruning. Ornamentals with high sap flow rates, such as maples and sweet gums, should be pruned in December; other ornamentals should be done in February or early March; common fruit trees, such as apples and pears, should be done in February or early March; stone fruits, such as peaches and apricots, are best done after flowering, since we get a crop only every so often to begin with; and evergreens are best done in late June.

When making cuts, leave at least a one-sixteenth-inch collar for proper healing. On large branches, make two cuts, with the first leaving a foot-long stub. These cutting procedures will reduce injury to tissues in the trunk or main branches. Don't bother with "pruning paint." This sealant will not prevent diseases from entering, since they probably were present as soon as the branch was cut, and any sap flow will loosen the covering.

There are a few other things to keep in mind when pruning:

1. Disinfect pruning tools with rubbing alcohol or bleach solution between each cut if you suspect diseases that can be transmitted.
2. Be very careful about pruning apple trees or mountain ash infected with fire blight.
3. Ash trees should not have much pruning done for about 10 years, due to potential borer infestations.
4. Expect lots of sap flow this year on most things, due to the warm winter we have had. This actually makes us feel worse than the effect on the plant.

For all you grape growers, the February or early March period is a good time to prune grapes. Train them to your trellis by leaving three good buds per branch. This number of good buds promotes grape and cluster size.

A final rule of thumb is this: "If you think you pruned too much, you're about right!"

You can even use a few of the pruned limbs from flowering trees and shrubs to brighten the home by forcing them. Just soak them in water overnight, then place in a large water vase or bucket.

[John Fulton, unit leader, University of Illinois Extension, Logan County Unit]