Alaska gardening interest booms, as tunnels extend growing season
Joseph Robertia, Redoubt Reporter
May 2, 2014
(excerpt) “This will be our third year with a high tunnel, and they’re unbelievable,” said Bill Lynch, of North Kenai, who along with this wife, Liz, led the discussion on this subject.
“We used to be limited to the usual Alaskan crops: cabbage, carrots, broccoli, etc. But now I grow fruit, like melons and blackberries, and artichokes and tomatoes,” he said. Having high tunnels increases what he grows, and it also increases how much and for how long.
“It used to be all the produce we grew would come ripe all at the same time, but now we can harvest fresh produce year-round. We got three full crops of carrots last year. We planted tomatoes by April 15th and by the first of May we were already harvesting. We ended up getting 400 pounds of tomatoes and 2,000 pounds of produce total last year from our unheated high tunnel. It would be 10 degrees outside, but inside the plants were fine,” he said.
Lynch said that the high tunnel was responsible for much of his success, but he also learned about using smaller low tunnels, within the larger one, to exponentially increase solar heat to plants. He said the concept is one that should be familiar to many Alaskans — dressing in layers to stay warm.
“Studies have shown the more layers, the more heat is retained,” he said. “Each tunnel over a plant is equivalent to moving one and a half zones warmer, or 500 miles south. This means a high tunnel will bring you to a growing season equal to northern Kansas, and adding a low tunnel in the high tunnel will move you to a growing season similar to Oklahoma.”