Peaches need plenty of leaves to mature

Q: I’ve attached a couple of pictures of our dwarf Bonanza peach tree, which we’ve had for three years. Each year it produces fruits but they never ripen. I remove 70 percent of the smaller fruits but the remaining fruits don’t get any bigger than a quarter and never ripen. What causes this and what can I do to get some ripe fruit? Would you recommend any other dwarf peach tree for our area.

A: Thanks for the picture. It helped a lot. Your tree should be much more full than it is. It is not demonstrating much growth at all. Although the leaves are dark green, the tree is not as full as it should be.

I sent you a picture of our genetic dwarf Bonanza peach tree at the orchard. You can see that the tree is full of leaves and fruit. The reasons for this are the wood mulch that we use (as opposed to your rock mulch), early spring fertilizer and adequate watering.

Each peach fruit needs about 40 to 50 leaves for it to develop adequately. Your tree needs more leaf cover to do this.

Q: I have 13 Italian cypress trees planted along a wall of my yard. They are about 30 years old, and there has been no change to their care or watering, yet they are all dying. They drop needles and die from the top down. I researched the problem on the Internet, and found two possible causes. The first was mites, and I followed the instructions for removal by spraying them with water, but it did no good. I found no mites, and this only increased the depth of dead needles on the ground.

The second possible cause listed was a disease called cypress canker, which apparently has no cure.

A: Italian cypress problems do occur on occasion. I agree that the two problems are usually mites and canker. Mites can be common when it gets hot. Canker is rare in Italian cypress, and much more common in Leyland cypress. In Arizona cypress it is usually borer problems .

Canker usually occurs when the soil is kept too wet, particularly during the summer months. Italian cypress comes from Mediterranean climates and prefers moisture in the winter and dry summers. They thrive in the heat and once they get mites it can cause their defoliation and death. Typically, they do not recover when they lose their leaves (needles).

Mites are fairly easy to diagnose. Needles look dusty in appearance and when slapped against a white piece of paper you can see these minute critters, which are about the size of a dot at the end of this sentence, crawling quickly along the paper. They spread from tree to tree quickly and the best remedy is soap and water hosings periodically during the summer heat.

Q: I noticed that when people ask you to recommend plants for the area you don’t help them. Why is that?

A: I don’t make plant recommendations because there are so many plant choices and choices are very subjective. So if the person will select five of their favorites, I will help them narrow their selections down to one or two from that point. Nurseries or plant recommendation guides will help people get their choices down to a few to start with. Otherwise I will be going back and forth with “No, I don’t like that one. Can you suggest another?” So the reader should do the initial cut to a few he or she likes.

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 e-mail at morrisr@unce.unr.edu.