GARDENING QUESTIONS
Various problems can cause fruit drop
Question: My plum and apricot trees bloom every spring, start to form fruit and about the end of June the fruit all falls off. Any suggestions?
Answer: Lack of pollination can prevent fruit from forming or cause it to drop before reaching full size. Some apricots and plums require two different varieties for pollination and fruiting. Make sure your have the right varieties for pollination and fruit set or self-fruitful varieties. Spraying insecticides at the wrong time can also reduce or eliminate fruit production. Read and follow all label directions when applying any chemical. Fruit trees also shed some, usually not all, fruit when they produce more than the tree can support to maturity. This is often referred to as June drop. Consider thinning the fruit to eliminate this problem.
Q: I have an Autumn Brilliance serviceberry that was planted last year. I noticed spots of powdery mildew on all leaves. Some of the leaves have brown spots also. What do you suggest I use on it? It has berries now that the birds are eating so I don’t want to use anything that is harmful to them. I also don’t want to lose this plant. What do you suggest?
Serviceberries (Amelanchiers) seldom have problems with insects and diseases. Our wet weather and high humidity so far this year have increased problems with powdery mildew, leaf spot, root rot and other diseases on a variety of plants. Treatment is usually not needed or recommended for diseases on serviceberry unless the health of the tree is in jeopardy. This can be a concern with newly planted and young trees. Timing is critical in controlling plant diseases. It is often too late to treat once the spots occur. All you can do is rake and destroy infected leaves to reduce the source of infection next year. A lightweight horticulture oil, like Summit Year Round Spray Oil, is an organic product that can help manage powdery mildew. Wait until the birds have finished feeding if you do decide to treat the powdery mildew. And as always read and follow label directions.
Q: Was last winter hard on Wisconsin roses? We have 12 roses in our yard, half of them Knock out type. In general we had to prune much more this spring and did replace one. I heard similar comments from friends and neighbors.
It was a difficult winter and challenging spring for roses and many other plants. The extreme cold and lack of snow early in the winter stressed or killed some plants. The wet spring with extreme fluctuations in temperature added to the stress. The waterlogged soil resulted in root rot and in some cases death. Many plants did eventually recover and eventually sent out new growth; others did not. Patience waiting for plants that appeared dead did pay off. And as you discovered, many plants needed quite a bit of dead wood removed.