By Darrell Blackwelder
SALISBURY — The weather is always a relevant topic concerning gardening, especially with unusual weather experienced over the past few weeks. In some instances, inconsistent weather may be the culprit for gardening woes. Below are a few questions received earlier this week that may be of interest.
Q: My tomato leaves are curling. They curled last year. What can I do to prevent this?
A: Researchers don’t really know the exact cause of tomato leaf roll. The overall growth of the plant does not seem to be greatly affected and yields are normal. This condition appears to be most common on staked and pruned plants. It occurs when excessive rainfall or overwatering keeps the soil too wet for too long. It is also related to intense sunlight, which causes carbohydrates to accumulate in the leaves. Some varieties of tomatoes are characteristically curled.
Q: My squash all got that squash vine borer in it last summer and it ruined my entire crop. What can I do to prevent this from occurring this season?
A: Home vegetable gardeners can take various measures to control the pest. It is important to till the soil in late winter to expose over-wintering insects to freezing temperatures. It is also necessary to rotate squash to another location in the garden each season.
Be sure to destroy vines in an effort to break their life cycle. If you have wilting vines, you can slit the infested vine lengthwise and remove borers or kill them with a long pin or needle. Placing soil over the slit stem after removing the borer encourages new root development.
It is also important to keep plants well watered after removal. Growers can also avoid borers by planting as early as the weather allows since borers do not emerge until early summer. A second planting of summer squash in early July matures after adult borers have finished laying eggs.
Insecticides can also be used. Both synthetic and organic insecticides can be sprayed or dusted on the stems at their base. Be very careful when using any insecticide as many are deadly to bees.
Two applications may be necessary to control vine borer adults. Aluminum foil on the base of the stems at planting will also deter the larvae.
Darrell Blackwelder is the County Extension Director with horticulture responsibilities with the North Carolina Cooperative Extension Service in Rowan County. 704-216-8970