Q: There are black bugs with a red triangle on their back all over the outside of my house, and some are coming inside too. My neighbor said they are boxelder bugs. What can I do?
A: When boxelder bugs are found congregating on plants, feeding on seeds or resting on exterior walls or surfaces, they can be sprayed with residual insecticides. However, most insecticides registered for this use are applied at a higher rate than that used for other plant pests. This higher rate can’t be used directly on plants; plus the spray may leave stains. The better pesticide to use is insecticidal soap applied directly to boxelder bugs. However, the soap spray will only be effective if it contacts the insect directly. They are relatively safe to use, but you still should read and follow label directions. The soaps can injure some plants.
Vacuum them up if they are coming inside. If squashed, they can leave stains, and they have an objectionable odor. It’s also a good idea to tighten up your house with screening and by sealing cracks or other entrances. A more permanent solution to a boxelder bug problem is the removal of seed producing maple trees from the neighborhood, although this is usually not practical. Removal of one or two problem trees from the area may help, since boxelder bugs usually overwinter near the trees that they feed on.
Q. What can I spray on my ornamental plum tree to keep it from forming little plums?
A. ‘Florel’ is a plant hormone that will prevent fruit formation if applied at bloom. Ethephon is a naturally occurring plant hormone, but when available in large qualities at bloom, it makes the tree think it is under severe stress, and the tree aborts most of the fruit. It can be used on a variety of ornamental trees. Alternatively, you could replace the ornamental plum with a more desirable tree.
Q. I’m new to gardening. What does “days to maturity” mean on a seed packet?
A. Days to maturity indicates the number of days it takes to grow the plant to a point when it can be harvested for consumption. The days to maturity rating is an estimate for all areas where the crop can be grown, so it takes some experience to know how the true days to maturity will work in your area. Generally, day zero for the count is at emergence from the soil.