How to Bend Tubing for Cold Frames

Cold weather greenhouses.

Cold frames are built out of metal tubing, which is bent into a dome-shape and either attached to a frame or directly to the ground. Hoop-house cold frames are built to cover each row of plants individually; they are too low to the ground to stand up in, but they are tall enough to accommodate whatever plants will grow in them. Taller plants will need a slightly higher row, which can be built out of 6-foot lengths of wire, while shorter plants will only need the space given by a 4-foot length.

Things You'll Need

• Two-by-four plank
• 3-inch screws
• screwdriver
• C-clamps
• Heavy gauge wire

Instructions

1. Determine the height of your cold frame. If your plants are taller, then you will need to cut 5- to 6-foot lengths of 10-gauge wire to support the row covers. Shorter plants will only need 4-foot lengths of wire.

2. Build a jig to bend your wire around. Mark the center point of your two-by-four plank and, along the top edge, drive a screw into the plank 6 inches off center on each side of the mark. Leave the screws sticking out of the wood by 1 inch. Screw two more screws into the plank half an inch below the first two. Screw two more screws into the lower edge of the plank, 1 1/2 feet off center, one on each side.

3. Clamp your jig to your work table so that it can't move as you bend your hoops.

4. Thread your cut wire through the jig, bending the middle of the wire around the the top-edge screws until the wire is centered in the jig, resting just inside the lower-edge guide screws.

5. Take the wire out of the jig and stick the ends into the ground on either side of your row.

Tips & Warnings

• If you are building a small raised-bed cold frame, you can drill 1/4-inch holes directly into the wood frame holding your raised bed together and then stick the wire into the frame instead of into the ground.

References

• New Mexico State University: Row Cover Vegetable Production Techniques