High tunnels are here to stay.

The USDA Natural Resources Conservation Service announced last month the High Tunnel Cost Share grant program is no longer an interim practice.

“The program has been tested and proven in the last four or five years,” said Meg Mueller, the NRCS Kenai district conservationist. “It is quite popular and proven useful.”

Alaska ranks second in the nation in numbers of high tunnels, Mueller said. Missouri has more, but per capita Alaska is likely in first place, she said.

In the central Kenai Peninsula area there are 79 high tunnels in use through the cost share program, and in Homer there are 161, Mueller said. Another 12 contracts have been approved, but not yet built, she said.

In Alaska growers use high tunnels as a method for season extension and a way to cultivate produce that could not otherwise flourish in the harsh northern climate, Mueller said.

“Production is so abundant and prolific, people tailor their seasons now,” Mueller said. “They don’t start as early and end as late because during the production season it is that much better.”

High tunnels, also known as hoop houses, are hulking metal frames, wrapped in a layer, or two, of polyethylene plastic. Plants are sewn right into the ground, unlike greenhouses where vegetables, fruits and flowers are grown in containers, according to the Kenai Soil and Water Conservation District website.

High tunnel users have the option between Gothic style, a sharply angled structure, or Quonset with a curved roof. The snow shedding Gothic high tunnels are preferable for the Kenai Peninsula, but will force a buyer to drop a larger sum on construction, according to the Kenai Soil and Water Conservation District website.

Seedlings accelerate to maturity inside high tunnels’ soil and temperature is enhanced in the enclosure, said Pam Voeller, NRCS Kenai Soil Conservationist.

This season the Kenai Water and Soil Conservation conducted a survey of local high tunnel owners, Voeller said. The majority of people who entered cost share contracts have maintained the practice, even after the three years of obligatory record keeping required through the program, she said.

People who previously felt that pressure to sign up while it was still an interim practice, now have time to thoroughly develop the site they plan to use for a high tunnel, including soil enhancement, Voeller said. They also have time to identify their needs and design a system integrating the high tunnel that will work best, she said.

The first wave of growers who started in the cost share program in 2010, its first year, are now finishing up the mandatory four-years they are required to stay in production, said Central Peninsula Garden Club President Marion Nelson. That means a foundation of experienced locals ready to help next year’s builders, she said.

Velma Bittick, who has had a high tunnel longer than the cost share program existed, said agriculture in Alaska takes time, patience and some experimentation.

Utilizing any method of production, be it an outdoor garden, heated greenhouse or sun-reliant high tunnel requires knowledge and development of the microclimate a gardener is growing in, Bittick said.

Even 10 feet of elevation makes a difference, Bittick said. Produce doesn’t grow well until the air and soil temperature reach 57 degrees Fahrenheit and thrive around 62 degrees Fahrenheit, she said.

People have tamed the temperatures inside their high tunnels so tropical fruit varieties can flourish, Mueller said.

The high tunnel incentive program was developed with just this purpose — to build high yielding regimens, Mueller said. If people establish a plan they carry through no matter what, they learn what does and doesn’t work, she said.

Advanced management means a more sustainable, productive peninsula, Mueller said.

The Cooperative Extension Service will be holding a High Tunnel 101 class on the Kenai Peninsula College campus on Oct. 30. To register call 907-262-5824.

Reach Kelly Sullivan at kelly.sullivan@peninsulaclarion.com.