Shoots, branch of cherry tree die, but fire blight is not the problem.

Backyard Q & A

March 11, 2001

Q. How do you get rid of fire blight in sweet cherry trees? At least that's what I think is wrong. Last summer, some of my young shoots wilted and died and one branch died back. I want to prevent the problem this coming season.

A. Cherry trees don't get fire blight. You may have a couple of different problems. Oriental fruit moth larvae may have entered the young shoots, causing wilting and death. Or the shoots may have been damaged by very cold temperatures. The branch dieback was probably caused by a canker disease. The answer to both problems is to prune out the affected shoots and branches. Make your cut at the branch junction below the noticeable damage.

Q. Powdery mildew attacks my beloved dogwoods each year, making the foliage unsightly. I have used Daconil fungicide in the past but am concerned about its effects on my dogs and cats. I read that baking soda is a good organic alternative to Daconil. Any truth to this?

A. Research conducted by the University of Maryland indicates that baking soda by itself is not an effective fungicide for controlling powdery mildew. However, ultra-fine horticultural oil, at a 2 percent rate, is an effective organic fungicide for use on dogwood and many other ornamentals. The most important time to spray is in early spring when the buds are opening and new leaves begin to unfold.

This Week's Checklist

1. Spray lime sulfur (an organic fungicide) before buds begin to swell to prevent peach leaf curl. Don't apply within two weeks of a dormant oil spray.

2. Monitor evergreens for spruce spider mites, which cause needles to turn yellow. Tap branches while holding a piece of white paper underneath and look for crawling specks. They can be controlled with a horticultural oil spray.

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