Pruning fruit trees winter can give you larger fruit in spring

On the day I am writing this column, it is cold outside. In fact, local weatherman Bob Reeves says it will be the coldest night of this winter season. He also says we are in for a warm-up during the next few days. Hopefully, by the time this column is published, you will be in the mood to read about gardening again.

Even though spring is at least six weeks away, it is time to get your fruit trees in shape. You need to plan on pruning your trees and applying dormant sprays during the next few weeks.

Most orchardists prune their fruit trees in February and March. I think they do this because that is the season when they have the time to get the job done. In addition, since no leaves are on the trees, they can get a much better view of the work that needs to be done.

Orchardists prune their trees for several reasons. First and foremost, they want to shape their trees so that fruit picking can be done efficiently. This amounts to keeping the crown low and widely spread. You can change the direction that a small branch is growing by cutting the branch just above a bud that is pointing in the direction that you want the branch to grow.

Fruit trees are also pruned so that the crown is kept open. You don't want to have a lot of small branches growing in the crown, which produces a dense crown when foliage develops. It is important to have a lot of air movement through the crown. Moving air reduces the amount of disease problems that can easily crop up when tree crowns are too dense.

Fruit trees set their flower buds in the late summer or early fall of last year. So when you prune at this time, you are removing some of the flower bud, and thus reducing the number of apples, pears or peaches that will develop. A tree has only so much energy that it can expend for fruit production. Therefore thinning at this time of the year results in fewer, larger fruits developing.

Pruning is not the only activity going on at this time of the year in the orchard. A dormant oil chemical needs to be applied. The oil, when dried, forms a seal around scale insects and other insects that are over-wintering in cracks in bark on under layers of bark. These insects must breathe even in the winter. The oil seal results in suffocation of insects found on fruit trees. Thus you don't have a large beginning population of potentially damaging insects present in early spring.

When making a dormant oil application, you must keep a couple of things in mind. First, make the application on a warm late winter day. It is important that the temperatures do not go below freezing on the night that you sprayed. It is also important that you cover the entire tree with oil.

If you have enough time and the season allows, I would suggest you make a second dormant application, not with the oil but with lime-sulfur. This old-time combination has been used for years to protect your trees, from not only over-wintering insects but also any disease problems that might be holding over. Make sure that at least two weeks, and preferably three weeks, separate the dormant oil and the dormant lime-sulfur application. Use of these two chemicals at the same time can cause extensive damage to susceptible trees.

Improve the quality of your fruit trees and enjoy the warm winter air while pruning. Also keep your eye on the weather forecasts and find those days when you can make those all-important dormant chemical applications.

Happy winter gardening!

Send your gardening and landscape questions to Paul Schnare at P.O. Box 699; Cape Girardeau, Mo. 63702-0699 or by e-mail to news@semissourian. com.