Pruning boosts trees’ productivity

Q: About 15 years or so ago, I read about fruit trees that have limbs that are bare for 18-24 inches before new stems and leaves come out. I have forgotten what the cause is and what the prevention or cure is. I have a peach tree with this condition and wonder how I could have prevented it or can cure it.

A: This can be a complicated area and it depends on what you might be referring to . If you are referring to fruit trees with new growth that has normal vigor but doesn't develop leaves, these can be referred to as "blind shoots" or "blind wood." People used to say it was due to a lack of cold winter weather.

If you are referring to new growth that is long and vigorous but lacks side branches, then this can be excessive vigorous growth that could be handled through summer pruning. If I want to keep a tree small, I try to prune as much as I can every late spring and early summer. This helps control tree size and keeps it smaller and more manageable.

Summer pruning is pruning only growth that has developed since spring. Growth older than this is not pruned until winter dormancy.

In our climate, I begin the summer pruning process in April at the University of Nevada Cooperative Extension Master Gardeners Orchard in North Las Vegas. The first growth that I remove is growth that is not worth keeping. These are vigorous shoots that grow straight up, straight down or toward the center of the canopy. Remove these at their point of origin. Once these unproductive branches are removed, I focus on shoots that I plan to keep or at least until I can see them better when the leaves drop in the winter.

Remember the most productive branches grow in the canopy at about a 45 degree angle above horizontal.

Any shoots that have grown longer than about 24 inches in length since spring are cut back to about 18 inches . I know your tree is a peach, but on trees that produce fruiting spurs along their branches (think short side shoots that produce fruit like apples, pears, plums, apricots) cutting them back sometime between April and June will encourage earlier fruiting along these branches .

Most peach and nectarines do not produce spurs . They bear their fruit along the length of 1-year-old branches .

In your peach tree's case, if branches are growing straight up, straight down or toward the center, remove them at their source. If new growth is growing excessively long, either remove it or cut it back to 18 inches in length .

Q: Recently I discovered some white round worms or grubs in my soil when I was planting. What are they and what can I do to get rid of them? Will they feed on the roots of the plants and kill them? Do you have any idea where they came from?

A: It is hard to tell without seeing what they actually are. There are some grubs that have six legs on the front and are grayish-white that we see a lot of in decaying organic matter. They also can feed on the roots of some plants, usually herbaceous plants like vegetables, herbs and flowers. These are frequently larvae of beetles rather than moths.

And because they are larvae , you will not have as many organic controls available to you. If plants are present, then you can use a soil insecticide drench. Things like pyrethrum, an organic pesticide, or a hard pesticide such as Sevin can frequently be found as a liquid drench.

If your soil does not have plants, then you can loosen it with a spade, moisten it, cover it with plastic and let it cook in the sun. Make sure that the edges of the plastic are sealed tightly to the ground so that the heat does not escape. This is called soil solarization.

By now they probably have stopped feeding, have pupated, turning into adult beetles, and will emerge to mate with other adults during the summer.

After mating the female then lays eggs in well-prepared garden soils or compost, where the young hatch and feed on decaying organic matter and soft tender roots of plants.

Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by email at morrisr@unce.unr.edu.