Blackwelder column: Answers to your garden questions

Published 12:00 am Friday, June 19, 2009

Unusual weather patterns over the past few weeks have many gardeners scratching their heads as to some of their problems.
Excessive rainfall, followed by cool temperatures and now high heat, do present problems. Below are a few questions posed by home gardens this week.
Q: My zucchini squash has very large vines and is very healthy, but has no fruit. What can be the problem?
A: Lack of bees for pollination is probably the problem. Avoid use of pesticides around squash or other cucurbits. Bees will eventually come back and pollinate the plant.
Q: My tomatoes are rotting on the end before they ripen. What can I do to control this problem?
A: Blossom-end rot is a physiological problem caused by lack of calcium. Poor watering practices, too much or not enough, or disturbing the roots by hoeing or plowing is a contributing factor. Mulch plants and provide ample water. Avoid cultivation when plants start to bear fruit. Liming will also help. Some tomato cultivars have a predisposition to this problem.
Q: My tomatoes are turning yellow on one side of the plant and dying. They did this last year so I moved the plants. What am I doing wrong?
A: your plants are probably suffering from Fusarium wilt. The variety you selected (Big Boy) has no resistance to this disease. Plant tomato cultivars that have resistance to this disease. Normally, it will be on the tag on the tray or flat of tomatoes with the letters V F N T on it next to the cultivar name. These letters signify that the cultivar is resistant to verticillium wilt, Fusarium wilt, nematodes and tobacco mosaic wilt.
Q: My green beans are pale green (these were brought into the office). I fertilized them earlier in the season. What seems to be the problem?
A: There is no disease problems associated with the beans. It is most likely a nutritional problem. All the rainfall over the past few weeks has leached the nitrogen out of the soil, giving them a pale green color. Extra fertilizer should remedy the problem. Soil testing the area will also help eliminate the problem.
Q: With this excessive heat cause any problems in the garden?
A: Excessive heat can cause blooms to abort on tomato and green beans. The plant will recover, but the fruit set may be limited. It will not be evident until a few weeks later. Also, some melons, like watermelon, can sunburn in excessive heat.

Darrell Blackwelder is an agricultural agent in charge of horticulture with the North Carolina Cooperative Extension Service in Rowan County. Call 704-216-8970.