A high tunnel is a plastic-covered structure that is used to grow crops. It can be temporary or set in place. Crops are usually grown in the ground within the high tunnel, and it's usually unheated.
There are many good reasons to choose a high tunnel, but these are the top 10 reasons you might want to build or buy a high tunnel for your small farm.
- Extended growing season. This is the single biggest reason to use a high tunnel. You can start plants in a high tunnel during the early part of the season when they would die or fail to sprout in unprotected ground. The high tunnel provides some solar gain, allowing the sun to warm the earth within it. You can extend the growing season into the fall and winter as well. This longer growing season means more income for your farm.
- Protection from weather and pests. Although not quite like growing in a totally pristine environment, high tunnels offer some protection from weather, like high winds or heavy storms, as well as pests.
- Starting seeds. Even if you don't use it for larger crops, a high tunnel can be a great tool for starting seeds for the small farm on a bigger scale than you can achieve in your farmhouse on a seed shelf.
- Growing alternative crops. The high tunnel can be a place to experiment with alternative crops that may require different soil or growing conditions than the rest of your farm. A high tunnel can be the perfect spot for these crops to be isolated and trialed.
- Low cost. Compared to a greenhouse, a high tunnel is cost-efficient. Because they don't require a heating system, you can save on the cost of figuring out heat and installing it.
- Possible tax savings. You'll need to check with your town and state, but in many places a high tunnel is considered a temporary structure, not a permanent one. Compared to a greenhouse, a high tunnel can save you from an increase in property taxes.
- More spacious than cold frames and polytunnels. For those who don't have anything else, cold frames and polytunnels can provide some season extension. But they can be difficult to maneuver under and require more attention and fussing. You can't walk into a cold frame. You can walk into a high tunnel, providing much greater access plus a larger area for growing crops.
- Irrigation control. Because a high tunnel shields the ground below from rains, you will need to provide irrigation via an automatic irrigation system. And although this is an expense, it gives you a chance to control how much water your crops get. In some cases this can be very handy.
- Easy to relocate. Unlike a permanent structure, a high tunnel can be moved fairly easily. Through the growing season, crops can be uncovered, while the high tunnel is moved to a new spot to start new plants. Some are even experimenting with high tunnels on rails that can be moved down a row easily, providing first-frost protection for tender plants early in the season, moved down to provide additional heat for peppers and tomatoes, then moved a third time to grow greens into the winter months.
- Grant for high tunnels. The USDA offers a grant for farmers who produce agricultural commodities to get a high tunnel. The grant is through the Environmental Quality Incentives Program (EQIP). There are some requirements that you will have to meet, but you will also receive support and instruction to help you meet those requirements.