, Newburyport, MA

July 24, 2013

Heat brings pests to gardens

Tim's Tips
Tim Lamprey

---- — Last week was one hot and humid week! It was so nice to have some cooler and drier air on Sunday morning.

An extended period of hot and humid weather usually brings two pests to our yard and gardens. The most common pest is the spider mite. These tiny insects are about the size of the point of a pin. Their numbers skyrocket in hot weather. They can go from an egg to an adult in four days! They suck juices out of the plant. When they have damaged a leaf on a plant, the leaf develops a gray color. Their favorite plants include verbena, rose bushes, dwarf Alberta spruce and other spruces and tomato plants, just to name a few. Once you spot the problem on your plants, it is important to react quickly and begin a program of repeat applications of insecticides. You will need to do repeat applications because this insect reproduces so quickly. If they are on vegetable plants, you must be very careful to use only insecticides that are labeled for use on the particular vegetable plant that you need to treat for the mites.

The other insect that appears during a long, hot summer is the chinch bug. This insect attacks lawns. During a hot and dry summer, it may be normal for a lawn to go from dark green to light green, yellow, and finally turn brown. If you have a section of lawn that goes from green to brown while the rest of the lawn stays green, you probably have chinch bugs feeding on your lawn. There is a simple test to check if chinch bugs have invaded. You will need a round metal can. A coffee can is probably the best thing to use.

Remove both ends of the can, creating a cylinder open at both ends. Go out to your lawn and go about 1 to 2 feet away from the brown area into a green area of the lawn. Take the cylinder and push one end into the grass. You may need a hammer to push the cylinder about an inch into the lawn. Fill the cylinder with water and wait a few minutes. If you see black and white insects floating to the surface, then you have chinch bugs. If you don’t see any insects, check several more places in the lawn just to be sure. There are both granular and liquids that you can spray on your lawn to control this pest. It is important to control chinch bugs early. This pest kills the grass and you will have to dig up and re-seed those areas damaged by this insect.

The heat has caused our vegetables plants to grow like crazy. You may find that some plants have produced flowers, but no vegetables have set. The reason is that some vegetables don’t set when temperatures are above 90 degrees. Tomatoes, unfortunately, are one of them. There isn’t a lot you can do about this. It will create a lull in your crop down the road, but the cooler temperatures we are having now will mean a new crop of flowers will set and you will have fresh vegetables soon.

Remember that your vegetable garden always needs moist — not soaking wet — soil, and a steady supply of fertilizer to produce the vegetables you want to harvest. Also make sure to have in place now your tomato cages or heavy wood or metal stakes to support your tomato plants and pepper plants. Once these plants set vegetables, they get top heavy and a strong thunderstorm or a few days of rain will cause the plants to fall onto the ground if they are not supported properly.

Well, that’s all for this week. There won’t be a column in the paper next week because of Yankee Homecoming coverage. I’ll talk to you again in two weeks.


Tim Lamprey is the owner of Harbor Garden Center on Route 1 in Salisbury. His website is Do you have questions for Tim? Send them to, and he will answer them in upcoming columns.