Spider Mites

(May 2012)

My wife and I have tried to find a solution to a pyracantha problem. The plant has developed black leaves and white chalky spots. She has applied a fungicide twice and there has been no real change. What can she do to fix this problem?

The problem could be several things at once. Pyracantha can get fireblight which will start on the tips and look like the plant was burned. The disease is spread during bloom by honeybees, and no control other than cutting it out can be done once you see the problem. Spider mites are also common problems on pyracantha and can cause the leaves to look white or mottled. They tend to be worse when it is dry--and so far this spring, it has been dry. I would suggest taking a plant sample in to your local county extension office to get a proper diagnosis so that you use the correct control measures.

(January 2012)

I have a very old (20 years) croton plant that has deep sentimental meaning to me. This summer I put it outside and it was very happy and turned beautiful colors. However, since I brought it inside, it has been dropping leaves. At first, I thought it was just adjusting to the climate change, but today I noticed fine web-like stuff in the crotches of the branches. as leaves continue to drop. I sprayed it with Neem oil and washed off the webs with Murphy's oil soap. I also moved it into my greenhouse so it can get more light and humidity. What else should I do to save it? Is there danger of whatever is on it infecting my other plants in my greenhouse?

There is definitely a chance that the insects will move from one plant to another, particularly in a closed environment of a greenhouse. It sounds like spider mites to me. The Neem oil and the Murphy's Oil soap should definitely help, but keep it isolated from your other plants and monitor it. Keep the soil on the dry side, but try spraying the foliage with water periodically, as spider mites thrive when dry. Don't expect miraculous new growth until the day length increases, but I would suspect it will rebound. The more light they get, the more colorful their foliage. Good luck!

(May 2008)

Each year I have tiny, black pests on the leaves of vegetables in my garden. They cause damage to my plants and are difficult and expensive to try to control. They are so tiny, they are almost invisible to the naked eye. You almost need a magnifying glass. I can only see them if I cut off some leaves and shake the leaves on a piece of white paper. Then I can see the tiny black dots move around. What are they and how do I control them?

The most common insect in the garden is aphids. They can range in color from black, red, green or yellow. They are small and tend to congregate near new growth or in the joints of leaves. Flea beetles are also small, but tend to jump with vigor when disturbed. Spider mites are really tiny but tend to be reddish in color. If aphids are the culprit, they can be controlled with a strong spray of water, insecticidal soap or Malathion. Be sure to follow label directions as to timing and harvesting. For a definitive diagnosis of the insect, take some into your local county extension office.

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