Garden Column for the Salisbury Post Darrell Blackwelder July 8, 2004 July has delivered its usual hot weather and excessively high humidity that we've learned to expect. Coping with the excessive elements often compounds other problems caused by insects and diseases. Below are questions posed earlier this week by homeowners that may be of interest to those trying to cope. Question: May squash plants look good early and produced some blooms, but failed to produce any fruit. What am I doing wrong? Answer: Squash and other cucurbit crops need bees for pollination. Lack of bees can limit fruit from these plants. Avoid spraying insecticides, especially Sevin around plants during the day. Question: My crape myrtle has white substance on the leaves. What is this and how do I control it? Answer: The problem is powdery mildew. It is caused by a fungus. If feasible, use a fungicide labeled for the disease. Larger trees may be impractical to spray for the disease. Question: How do I get rid of poison oak in my yard? Answer: Poison oak or ivy can be controlled with directed sprays of glyphosate (Roundup) 2% solution. It is easiest to kill just before or just after bloom. Broad leaf weed or brush killers will also control the plant and will not kill grass. Always read and understand the label before applying any pesticide. Question: Mimosa trees were in full bloom a few weeks ago and are very beautiful. I understand you discourage people from planting the tree. What is the rationale for not recommending the tree? Answer: Mimosa trees you seed blooming are generally considered short-lived trees due to a root fungus that thrives in our soils. There are some trees resistant to the fungus, but are difficult to locate. This species just does not live well in this area. Question: I have bagworms in my pecan tree. What can I do to eliminate them and keep them from defoliating my tree: Answer: The insects you're speaking of is not bagworms, but fall webworms. The immature insects make a large web and generally not kill trees. Insects can be control by knocking the nests down exposing the worms to birds and other natural predators. Question: I have this yellow weed that is killing my flowers. It has tendrils and looks like spaghetti. What is this and what do I do to control it? Answer: What you have is a parasitic plant called dodder. It is a true parasite that lives off other plant tissues. It is very difficult to control. Soil sterilization or rotation of plants is the only feasible method of controlling this pest.