May 30, 2006
Study will help farmers produce early crops
CARBONDALE, Ill. -- It was only May 1, but several of Alan Walters' bushy plants already sported golf ball-sized green tomatoes on leafy stems.
"Everyone loves early season tomatoes," he said, as he pulled the plastic covers off a row of plants in a vegetable plot at Southern Illinois University Carbondale's Horticulture Research Center southwest of campus.
"The earlier you get them to market, the more you can get for them — anywhere from $2 to $2.50 a pound if you sell directly to the consumer. By Aug. 1, when everyone has tomatoes, that will drop to $1 a pound or less."
Walters is an associate professor in the College of Agricultural Sciences' plant, soil and agricultural systems department. He is starting the second year of a study aimed at helping farmers produce early crops that will bring top dollar without much of a cash outlay up front.
"Last year, we were harvesting tomatoes the first week of June," he said.
"Usually, if you have tomatoes before the Fourth of July, you can get that premium price. After that, the market becomes flooded."
In this region, tomato plants need a little help in getting off to an early start. At SIUC, that help comes from "row covers" — plastic or cloth "blankets" draped over small metal hoops so that each row looks like a very long, low-to-the-ground wagon train.
"We're trying to modify the environment," Walters said.
"We usually get a frost or two sometime in April, which will kill or stunt the plant significantly. The row cover can give you 5 to 10 degrees of protection. And you need the metal hoops to keep the plants from being crushed when you put the row cover on."
Individual row covers, available from various horticultural supply and irrigation companies, cost relatively little. While you can buy covers big enough to protect an entire garden plot and tall enough to stand up in, these "high tunnels" cost between $3,000 and $4,000.
"That's a significant investment — it's like putting up a little greenhouse," Walters said.
"It would take growers several years to get their money back, even if they were getting those premium prices."
At the horticulture center, Walters is comparing performance of plants under slitted polyethylene with that of plants growing under cloth covers. He's also looking at how covered plants do compared with those left to fend for themselves.
"We planted all these outside on the first of April," he said, pointing to the rows of plants.
"You can see that the ones with no covers on them at all are anywhere from a third to half the size of the others."
Walters is also looking for the top performers in early season cultivars.
"We've expanded a bit from last year," he said. "We have five cultivars here at the hort center and 18 at a farm down in Cobden."
While Walters' research targets commercial vegetable growers and farmers who sell directly to consumers, his methods would work equally well for impatient backyard gardeners eager for the unrivaled taste of homegrown tomatoes. While it's too late to get early tomatoes now, keep these tips in mind for next year.
• Buy some covers. If your local suppliers don't carry hoops and row covers, you can find them on the Web. Slitted plastic will cost less, but cloth will hold up better.
"Normally, you can use the slitted plastic two to three times, though this year we had some really bad storms come through, so we're not going to be able to use these again," Walters said.
"We've used the cloth covers five or six times now."
A word of caution: Some row covers feature a zipper. Sounds like a good idea — unzip when it's warm, zip back up when temperatures dip. But that means you have to go out and attend to them every day, and if you don't get to them in time on sunny days, you could have fried green tomatoes — and not in a good way.
"You can get up to 115 degrees or more under that cover," Walters said. "You can avoid that with a slitted cover or a cloth cover for ventilation."
• Choose an early season variety. Last year, Walters had good luck with both Sunshine and Sunbrite cultivars.
• Start large. Rather than using cell trays to plant his seeds, Walters sows 20 to 30 seeds into a container that resembles a grocer's small berry box, then transplants the seedlings directly into 4-inch pots. You should, too.
"The larger the volume of the root, the earlier the production will be," he said.
• Make ridges, not beds. While you're waiting for your seeds to sprout, head out to the garden and turn the soil over, then form it into ridges — they warm up faster than flat beds do. Install a simple, inexpensive drip irrigation system to take care of watering needs, fertilize and cover the ridges with a layer of black plastic. The plastic will warm the soil, speeding fruit production process. Later in the season, it will retain moisture and keep the weeds down, too.
• Transplant. When the seedlings have four to six leaves or reach roughly 1 foot in height, it's time to put them into the ground. Make a hole in the black plastic — not too big; you don't want to give potential weeds the chance at more sun and water —and insert a tomato plant.
• Don't forget the aftercare. Give them about a month to grow (Walters shoots for April as his growing month), remove the covers and fertilize normally. When June rolls around, pick your ripe tomatoes, eat and enjoy.
Leading in research, scholarly and creative activities is among the goals of Southern at 150: Building Excellence Through Commitment, the blueprint the University is following as it approaches its 150th anniversary in 2019.
(Caption: Man the tomatoes! — Row covers can help you go full speed ahead in producing early tomatoes, as horticulturist S. Alan Walters demonstrates in this garden plot southwest of the Southern Illinois University Carbondale campus. )