How to Build a Tunnel System (Hoop House)

Growing and harvesting veggies from your own garden is very rewarding. Here in the Willamette Valley, winter is fast approaching and gardens are starting to slow down in production. If you want to extend your growing season, here is a simple solution: A Garden Tunnel (aka a Low Hoop House).

Garden Tunnels act as mini-greenhouses. They help to protect your plants from winter weather and freezing temperatures. Covering your beds in this manner also keeps the soil warmer for a longer period of time, thereby extending your growing season farther in to the fall/winter.

Many of us have raised beds in our gardens and adding a garden tunnel to them is an easy task. One of the simplest methods we’ve seen is to use rebar and PVC pipe to make arches over the raised bed. These arches are then covered by floating row fabric. Typically available at your local garden centers, this fabric still allows sunlight and water to reach your plants.

Step 1: Hammer pieces of ½’ rebar that are 18” long into the soil of the raised bed along its edge, every 5’. You will need 2 pieces of rebar for every 5’ of bed length, one for each side of the bed. When installing the rebar, make sure they lean at a 34-45 degree angle towards the inside of the bed and leave about 6” above the soil surface.

Step 2: Take a 7’ length of ¾” PVC pipe and slide one end of it over the rebar; bend the pipe over the raised bed and slide the other end of the pipe over the rebar on the opposite side of the bed. Repeat this process every 5’.

Step 3: Install the floating row fabric. Use a piece of fabric 83” wide and 8’ longer than the length of the bed. This will give you an extra 4’ to enclose each end of the Garden Tunnel. Along one edge of the fabric sew a sleeve and insert a length of PVC pipe that is the same length of the bed. This will be your “door” to incover the tunnel. Lay the floating row cover over the top of the PVC hoops. Attach it to the back side of the bed with ¾” row cover clamps. You will need approximately 2 clamps per hoop. Then pull the fabric over the top of the hoops and close the door. The extra fabric at each end can be weighed down with rocks or sandbags. To ventilate or harvest your veggies, simply open the door.

Step 4: Enjoy your extended growing season!

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