Row Tunnels For Winter Vegetables

As fall has moved into winter, temperatures will continue to go well below freezing.  Although most winter vegetables can tolerate temperatures slightly below freezing, tunnels offer a way to extend those cool weather vegetables when the temps dive low.  We have had our 1st significant freeze and temperatures that plunged into the low twenties. In anticipation of the colder temperatures, I got some row tunnels to protect my winter garden during the really cold days.

Here is what I bought on Amazon to make my garden row tunnels:

The polytunnel is also known as a hoop tunnel, hoop greenhouse, row covers, or hoop house. They are typically made of steel and covered with polyethylene.  They usually are semi-circular and elongated. The interior will heat up because of incoming solar radiation. The heat from the sun will warm the plants and soil.  The heat will be retained inside the tunnel for a period of time. They are basically mini greenhouses.

You can give frost sensitive plants some protection by covering them with floating fabric or creating tents of plastic stretched over hoops. Even though there may be snow on the ground, the temperature under the low tunnel is often just right for growing cool season vegetables such as beets, spinach, and lettuce. The row covers I have used expand like an accordion and collapse for easy storage. They are plastic attached to heavy wire. The row covers can also be used to protect plants from insects as well as cold weather. They would also be beneficial for newly planted plants in other weather conditions such as windy days.

The tunnels can be very large or simply row covers.  I use row covers since my winter garden is small. Some tunnels are very large and have humidity and temperature controls within the tunnel.  It resembles a greenhouse set up. I have found row covers work well for small backyard gardens. When the outdoor temperature rise, I can easily remove the tunnels. As the sun begins to move north in late winter, venting the tunnels is important so they do not overheat as the sun moves position. As the winter has mild days it is a good idea to remove the tunnels. This will allow for hardier plants and make the most of bright days.  Tunnels can heat up quick so ventilation will be needed.

Here are a few vegetables that do very well in a low tunnel in winter and late winter:

• Lettuce
• Beets
• Kale
• Chard
• Broccoli
• Cabbage
• Scallions
• Spinach
• Brussels sprouts
• Asian greens

By the end of March I will remove the tunnels and store them for future use.  If they are needed for a sporadic cold event, they can be reapplied. Since the tunnels I use are small, they can easily be placed back over the rows for protection. Having manageable row covers makes it easy for application and removal.