Blackwelder column: Tips for tomato growers

Published 12:00 am Wednesday, December 2, 2009

Many garden center operators have told me the best selling plants this spring are vegetables, especially tomatoes.
Increased fuel and food prices have prompted many to try their luck and grow a few tomatoes to help offset the grocery bill.
Tomatoes are the favorite vegetable grown in Rowan County, and many home gardeners have already planted their early crop. I usually receive an abundance of questions as soon as the plant begins to set fruit.
Below are a few mistakes by home gardeners, but there is still time this season to remedy some of these problems in the quest for the perfect tomato.
– Many home gardeners don’t have their soil tested before planting.
This leads to guessing as to what type of fertilizers are needed for optimum growth. Many tend to over-lime and fail to add needed nutrients for optimum
growth.
– Tomatoes are extremely heavy feeders and need a constant source of fertilizer. Most fail to side dress with extra fertilizer after the plants start to set fruit. Fertilize every four weeks with two tablespoons of 10-10-10 per plant to maintain vigor and produce large fruit.
– Tomatoes need full sunlight most of the day. Partial shade from trees or buildings limits production and quality of fruit. Vines become dark green, tall and spindly, producing few fruits.
– Some plant the wrong variety for this area. Many of the older varieties have no resistance to fungal and bacterial diseases. Before purchasing seed or plants, make sure the plants are VFNT resistant tomatoes:
– V (verticillium)
– F(fuscarium)
– N(nematode)
– T(tobacco mosaic)
For example, Big Boy, German Johnson and Fantastic are two varieties that have no disease resistance and can be difficult to grow.
– Home gardeners fail to spray with fungicides. Tomatoes are susceptible to a range of both fungi and bacterial diseases.
Fungal diseases during damp, humid weather can defoliate plants within days. That leads to small, poor quality fruit. Maneb, zineb, Bravo, sulfur and copper sprays are just a few fungicides home gardeners can use to control foliar diseases.
– Incorrect irrigation or watering practices lead to blossom end rot, which is a calcium deficiency aggravated by too little or too much water. Blossom end rot is characterized by black rotten spots on the blossom end of the tomato just before ripening. These plants require even moisture during periods of drought. Drip systems or soaker hoses coupled with a layer of mulch helps retain even moisture. Lime is the source of calcium , which needs to be added to the soil before planting.
– Many people are surprised how well newer varieties perform and taste. Newer varieties are not only disease and heat resistant, but have good flavor. Plant your favorite, but always try a few new varieties each year.
– Improper insect control can doom your plants. Aphids are usually the first insect to attack tomatoes. Most people use Sevin, but that won’t control aphids. Insects can be a real pain late in the season, and if you’re not prepared to spray during late summer, fruit worms and tomato horn worms eat away at your tomatoes.
Darrell Blackwelder is an agricultural agent in charge of horticulture with the North Carolina Cooperative Extension in Rowan County. Contact him at the N. C. Cooperative Extension Service, 2727 A Old Concord Road, Salisbury, NC 28146, or visit www.rowan.ces.ncsu.edu.