joplinglobe.com; By Andra Bryan Stefanoni: GALENA, Kan. — Temperatures haven’t risen much above freezing in the past week on a patch of land between Galena and Riverton, but that didn’t stop Tim and Violet Green from harvesting a few hundred pounds of tomatoes.
The bounty was picked from plants that are not being grown hydroponically or in pots. They are growing at ground level in Kansas soil.
Bright red, shiny and the size of grapefruit, the tomatoes were the product of seed the couple started in July.
“We’re the only ones I know of who grow all winter within about 200 miles,” Tim Green said.
“They’re called high tunnels,” he said of the long, rounded structures in which the retired couple also grow several varieties of lettuce, radishes, onions, cucumbers and green peppers.
“We have all the fixin’s for a salad, any time you want it,” Violet Green said.
A high tunnel, or hoop house, is a low-cost version of a greenhouse that can help market gardeners extend their growing season in order to improve the profitability of their farms.
According to the Missouri Vegetable Growers Association, high tunnels can be as simple as pipes or other framework covered by a single layer of greenhouse-grade 4-millimeter to 6-millimeter plastic sheathing. Typically, they aren’t outfitted with electricity for heating or cooling.
In 2001, research by the Bradford Research and Extension Center at the University of Missouri-Columbia evaluated the yield performance of several tomato cultivars within a high tunnel and in the field. The study found that high tunnels significantly enhanced the yield of the tomatoes.
“Based on the result in this research,” the study concluded, “it is possible for a grower to have vine-ripe tomatoes from mid-June until October in the central Midwest by using high tunnels as a complement to field production.”
But the Greens took it one step further. “We installed wood-fired furnaces for times when the temperatures really dip,” Tim Green said. “Our only cost is labor.”
Hence their crop of cucumbers, romaine lettuce, green peppers, and row after row of Red Deuce, Red Bounty and Carolina Gold tomatoes that are producing in late December.
During the recent onset of colder weather, Tim Green has bunked in a sleeping bag on a cot next to one of the furnaces, and he wakes several times a night to feed them more wood.
“When you wake up cold, that’s when you know you need to feed it,” he said.
The Greens use drip irrigation via a network of tiny spouts to each and every plant, and they practice heavy pruning to keep the plants from getting too wet and overgrown.
“They must have good air circulation,” Violet Green said.
The couple have relied on a fair amount of trial and error.
“We learned that in here, the time the plants take to mature is about 20 days longer,” Tim Green said. “The seed packet says 73 days, but in here we plan on 93. There is less light — it’s diffused — so it slows down photosynthesis.”