Q. Each year, my vine crops are affected by the larva of the Squash Vine Borer. I have tried powder pesticides, but find that I have to apply them almost daily due to early dew and frequent spring rains. I would like to cover the plants with a fabric instead. Can you tell me what type of fabric to use, what weeks out of the year to apply it and when it is safe to remove the fabric? Also, can you tell me the time of year that these pests lay their eggs in the stem of the plant? By the time I see the telltale sawdust, it’s too late. I have also tried slitting the stem of the plant open and removing the larva by hand with moderate success. Obviously, the plant is damaged, and the yield is reduced.
– Dawn Runyon, Geneva, Ind.
A. Jokes abound about an overabundance of zucchini but I, like you, am often left looking at a pile of wilted foliage and forced to beg for squash from my borer-free gardening friends.
The larval stage damages the plants. The way to avoid larvae is by preventing the adults from laying eggs there. This begins in June and continues for four to six weeks. During this time, you can protect the plants with a floating row cover over them, but it must be removed to allow insects to pollinate the flowers. Unfortunately, it’s difficult to allow the pollinators in and keep the vine borers out! Alternatively, you can wrap nylon stockings or aluminum foil around the stems, or inspect and remove eggs as they’re discovered.
Plant a second planting in mid summer after the hatch period is over for another chance at harvesting zucchini. Select an early-maturing variety and hope for a late frost in the fall. You can also plant a very early crop of Hubbard squash to act as a trap crop.
Chemically, insecticides should be applied from the middle of June and reapplied every seven to 10 days for four to six weeks. Make sure you target the stems. Carbaryl (Sevin) is labeled for borer control in gardens. Or try the new products containing permethrin or esfenvalerate as an active ingredient. They have good residual activity and may give you the best control.
If your plants are attacked, remove the borer as you mentioned, and cover the vines with moist soil at the leaf joints to encourage secondary roots that can support the plant. At the end of the season, make sure all plant debris is removed from the garden. Till the soil in the fall or spring to destroy overwintering cocoons.
Q. When composting egg shells, does the egg white in the shell need to be cleaned out, or can the shell go into my compost as is?
– Cassandra D. Milam, Lafayette, Ind.
A. It makes no difference to the compost or the eventual soil it produces. However, including certain foods will attract more animals to your compost. Meats, fats and oils are usually omitted from compost because they attract rodents, although I know gardeners who compost absolutely all food scraps. They spread it on a field away from any buildings and tolerate all the animals that show up to partake of it. I include unwashed egg shells in my compost on a regular basis and don’t attract any pests. Recently, however, I put salted peanuts in the shell on the compost pile and awoke to a tipped over bin, knocked over flower pots and compost spread over the yard! From now on, I’ll keep it simple, including only fruit and vegetable scraps, egg shells and garden clippings.
Q. We have many sweet gum trees in our yard, which produce many gumballs that have to be picked up by hand before we can mow. Is there any way these trees could be treated so they won’t produce any gumballs?
– Lou Eckerle, Jasper, Ind.
A. Florel Fruit Eliminator contains Ethephon, which can reduce fruit set when properly applied. Other products include Naphthalene acetic acid (NAA), which is often sold as Fruitone N or App-L-Set. Home gardeners may find this difficult to find in small-sized packages. Effectiveness varies with chemical application. The rate must be carefully adjusted. Too low of a concentration can actually increase the number of fruit that are set. Too much can cause plant injury. Timing of the application is also crucial. Read and follow all label directions carefully! Nothing can be done after the trees have already set fruit, but this might be an option for next year.
Q. I inherited two shamrock plants, and I really like them, but after a few months, the leaves all turned brown. What sort of light do they need? Will being near a register harm them?
– Alice Klaserner
A. Shamrocks grow well in average house temperatures and especially prefer cooler temperatures at night. Bright, indirect light is acceptable, but a few hours of direct sunlight will help encourage blooming. A sunny east- or west-facing window is ideal. Avoid the drying air from a register.
Water the plants when the top of the soil feels a little bit dry, but be careful not to let the soil get too dry, since the roots are shallow. Use a fertilizer for blooming houseplants, according to label directions.
After blooming, it’s a good idea to allow plants a rest, otherwise known as a dormant period. During this time, let the soil dry a bit more than usual and discontinue fertilizing. Resume normal plant care in about two months.