North Florida weather brings its ups and downs, and there are times during the winter season when the downs are low enough to trouble even cold-tolerant crops. Gardeners who wish to keep their plants growing as long as possible, or give them a head start in the spring, may want to consider installing low tunnels.

The term ‘low tunnel’ refers to a structure used for season extension that is usually made of hoops covered with some material, such as fabric or plastic. A low tunnel, as you might surmise, is low to the ground, like a miniature greenhouse that just covers the plants. They are usually no more than a few feet in height. A high tunnel, by comparison, is tall enough to walk in, but with a similar sort of construction.

These are versatile structures, which can act as more than just protection from cold. Low tunnels can be easily modified to provide extra shade for crops during the hottest months. A lighter fabric or fine mesh can also be used as protection from insect pests. Low tunnels can be constructed to stand on their own or may be integrated into a raised bed. They may even be placed inside a larger structure such as a high tunnel to offer a double layer of protection.

An example of a low tunnel using wire hoops and plastic mulch to prevent weeds. Photo credit – B M. Santos, UF / IFAS Extension 

Pipe Bender for bending hoops for low tunnel systems. Image Credit Evan Anderson, UF / IFAS Extension

The cover of a low tunnel can be plastic, fabric, shade cloth, or even insect netting, depending on the needs of the crop. The hoops that hold the cover may be made of any sturdy material, such as wire, pieces of PVC, or metal electrical conduit. Hoop benders are available to help bend metal conduit to the correct shape. For more information about low tunnels, please see this EDIS publication.

Evan Anderson
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