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What is a high tunnel?

What is a high tunnel? Although there is no real hard and fast definition of the terminology, a high tunnel is basically a frame large enough to walk within covered by clear plastic. Although a high tunnel looks like a greenhouse, what differentiates the two are two key elements. One is the fact that unlike a greenhouse, the sides of a high tunnel can be rolled up and down to help regulate temperature and humidity within the structure. Two, and this is an important one for me, no fossil fuels are used to heat the structure – only the power of the sun. Although the lack of supplemental heat limits the variety of plants that can be grown in the colder months (i.e. you can’t grow heat loving tomatoes or basil in a high tunnel in New Hampshire in January) there is a certain satisfaction of harvesting fresh produce year round with energy harnessed directly from the sun.

Outside = 43 degrees, Inside tunnel… nearly 80!

The high tunnel concept is not new but has actually in one form or another has been used for centuries. The concept has gained recent exposure/revival through USDA’s “Know YourFarmer, Know Your Food” initiative – a cost share initiative with farmers across the United States aimed at increasing production of fresh local food year round while simultaneously reducing transportation costs and dependence on fossil fuel use for vegetable production. Year round, high tunnels provide protection from wind and rain which can result in increased crop yields and improved quality as well as decreased incidence of pest and disease problems.

The tunnel also provides us a space to start our own seedlings.

Last spring our farm was fortunate to be chosen to participate in this important initiative. With this new structure our main focus will be to grow a greater variety of vegetables year round which will be used to prepare our decadent three course candlelight breakfasts each morning for our Inn guests as well as share with our cottages and farmhouse guests that choose to cook during their stay with us at our New England farmstay. With thoughtful selection of cold hardy varieties (FedcoSeeds, an employee owned Maine seed cooperative, does a great job indicating cold hardy varieties they offer) and careful timing of planting we will be able to start crops much earlier in the spring and harvest a variety of fresh produce much later into the season and even some varieties like salad greens and some root crops year round.

Anyone growing vegetables, even on a small scale can benefit from the high tunnel concept. We purchased our high tunnel kit from Ed Person at Ledgewood Farms in Meredith, NH, but there are numerous sources online – everything from ready-to-build kits to low cost do-it-yourself how to instructions which can be built in all shapes and sizes according to your available space. If you have limited space to garden where you live, consider a cold frame made from used windows and hay bales. The point is it’s possible to grow a greater variety of fresh produce year round (or nearly so) without a lot of technology or cost – anyone can extend Mother Nature’s growing season and if you’re a serious gardener (and/or serious consumer of fresh foods) you’re not going to want to do without one! Below are some comparison photos taken this morning of both our outdoor garden and inside our high tunnel to demonstrate the drastic difference in plant growth and development between the two. Again, no fossil fuels, just a piece of plastic ten feet over my head.

Seascape ever bearing strawberry plants outside in our no till garden beds.

Seascape ever bearing strawberry plants transplanted inside the high tunnel in mid-October. Yes, those are blossoms and even fruit is starting to form on many of the plants and it’s only mid-April.

Stiff-neck garlic just waking up in their outdoor beds.

Stiff-neck garlic planted inside the tunnel on same day we planted the outside beds. These beds should mature 3-4 weeks earlier than the outside beds and yield @ 30% larger heads of garlic.

Self sown cilantro in the outdoor beds.

Cilantro started last October inside the high tunnel which we’ve been enjoying and sharing all winter and spring.

Planted last October this is one of Fedco’s cold hearty varieties called Red Tinged Winter Lettuce. Although started late, it “hibernated” through the coldest part of the winter and then started growing again in early February.

A winter hearty spinach varieties from Fedco. Although also planted late in October we’ve been enjoying since about the first of March.

We encourage you to come and see our high tunnel first hand while at our New Hampshire B&B and see how easy and gratifying it is to extend the growing season and enjoy enjoy home grown fresh produce year round.

Happy growing! Jackie, Innkeeper, Inn at Valley Farms

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