Hoophouses

Hoophouses are growing in popularity as a way to protect plants from a variety of threats.

Traditionally used in commercial agriculture, hoophouses are similar to cold frames, greenhouses, and row covers in that they provide a physical barrier between frost, insect pests, and disease vectors and your crops.

Open-ended hoophouses (Val Vannet) CC BY-SA 2.0

Hoophouses are also known as poly tunnels. grow tunnels, high tunnels, and hoop greenhouses. Hoophouses are typically created from steel frames that are covered with plastic (polyethylene) sheeting. These frames can be square or semi-circular.

Hoophouses create heat

Hoophouses extend the growing season by several weeks by increasing temperatures. This can be done with mechanical heaters, or with passive solar heat. In areas with extreme cold, smaller hoophouses are placed under larger versions, creating a buffer zone. As the sun’s rays warm the plants and soil within a hoophouse, the plastic sheeting slows heat loss. The heat can come in, warming the plants and soil, but it cannot escape as fast, so temperatures continue to rise. This provides the warmth needed by many sun-loving plants, such as strawberries, raspberries, blackberries, eggplant, basil, and peppers, and  As temperatures become too hot, fans and other forms of ventilation are added at either end, along with other helpful equipment.

Commercial multi-span hoophouse (Kattegatt) CC BY-SA 4.0

Hoophouses offer control

Another benefit of hoophouses is that they allow growers to manipulate humidity, along with temperature and air flow. Crops prone to fungal diseases can receive extra air flow with the use fans. Hoophouses also provide protection against strong winds, hail, sunburn damage, and sudden, unexpected cold. In areas with too much heat, misters can be installed inside hoophouses to keep the environment conducive to strong growth. All this protection allows fruit and vegetables to develop at a steady pace. It also allows them to be grown during traditionally unproductive seasons, and it helps more sensitive plants overwinter without too much damage. Hoophouses also offer protection against many pests.

Backyard hoophouse (Kattegatt) CC BY-SA 4.0

Pests blocked by hoophouses

Most flying insect pests (and neighborhood cats) are thwarted by the walls of a hoophouse. Not only are the plants harder to see or smell, the plastic wall creates an impenetrable barrier. This protection can extend to birds, rats, and squirrels, but only up to a point. Once these pests realize there is food inside, they will work harder to find a way in. The real protection is against insects that act as vectors for disease.

Hoophouses in the home garden

Smaller versions of commercial hoophouses are now available for purchase for the home garden, or you can create your own, using PVC or conduit.

If you had a hoophouse, what would you grow in it?