Blackwelder column: Early tomatoes grew up in a greenhouse

Published 12:00 am Thursday, May 24, 2012

SALISBURY — Garden centers and retail outlets are having a banner year selling vegetable transplants, especially tomato transplants. Both experienced and novice gardeners long for fresh, homegrown tomatoes.
Late June and early July is usually the peak of the season, when field tomatoes ripen. However, Steve Eagle and son Jeff are selling ripened field tomatoes at the Salisbury Farmers Market. Eagles Produce has taken a commercial field tomato and produced it in a greenhouse for customers at the market and at the vegetable stand on Old Mocksville Road.
With a bit of experimentation and risk, the Eagles have converted a field grown tomato cultivar into a nontraditional greenhouse tomato crop. Crista, normally grown as a field tomato, is now providing the grower beautiful ripened tomatoes as greenhouse tomato.
Eagle planted the tomatoes indoors the week after Christmas, in the same method as he would have planted outdoors in the field. Planted on black plastic, with drip water lines below, the plants are treated just as an outdoor tomato crop.
Unlike traditional greenhouse tomatoes, which can produce fruit over a long period of time, the Crista tomato cultivar is a determinant tomato variety that produces a large amount of fruit over a very short period of time. Determinant tomato plants are also shorter in height, requiring staking, but over time less labor intensive than traditional greenhouse tomatoes. Eagle reveals that each tomato plant has the potential to produce 20 pounds of fruit during this growing season.
Obviously, growing field tomatoes nontraditionally in a greenhouse allows plants to grow without danger of frost and get to market early under conditions of reduced disease and insect pressure. This also allows little or no pesticide usage, a plus for both consumer and producer.
One drawback to growing tomatoes indoors in a greenhouse may be pollination. Tomatoes rely on wind and plant movement to pollinate. Tomato pollen is released between 10 a.m. and 4 p.m. on dry, sunny days. Pollination is most successful midday when it’s warm and the humidity is low. The wind is usually sufficient to pollinate the tomato flower. But in a greenhouse there is no breeze and the flowers need help with this vital task. Commercial greenhouse producers often use specially designed tools that gently vibrate flowers to distribute the pollen. Other producers may employ sterile bumblebees released in tomato greenhouses to implement the task. Eagle creates a windstorm with his backpack blower to help with pollination.
The Salisbury Farmer’s Market is open on Wednesdays and Saturdays 7 a.m.-noon. You may want drop by and purchase some fully ripened, locally grown tomatoes.
Darrell Blackwelder is the County Extension Director with horticulture responsibilities with the North Carolina Cooperative Extension Service in Rowan County; 2727 A Old Concord Road; 704-216-8970