How to Build a Cold Frame PVC

Traditional cold frames are often permanent structures.

Cold frames are commonly used in cool climates to give garden vegetables a head start or to protect plants from wind, cold and frost. Traditionally, cold frames are permanent structures constructed of wood or concrete block with lids made of hinged frames fitted with single or double glass panes. However, you can easily build a simple, inexpensive and portable cold frame from PVC pipe and a few other supplies that are readily available at your local hardware store.

Things You'll Need

• 1 1/2-inch diameter, thin-walled PVC pipe -- 4 10-foot lengths
• Three-way connectors for 1 1/2-inch diameter PVC pipe -- 4, unthreaded
• PVC saw or hacksaw
• PVC primer
• PVC cement
• Plastic sheeting -- 6 mil, 6 feet by 12 feet
• Utility knife
• Plastic zip ties

Instructions

Construct the PVC Frame

1. Cut two of the 10-foot PVC lengths in half to create four 5-foot lengths of pipe.

2. Apply a 1/2-inch wide band of PVC primer around each end of two 5-foot lengths of pipe. Allow to dry for a few minutes, according to the manufacturer's recommendations.

3. Apply a 1/2-inch-wide band of PVC cement around each end of the two 5-foot lengths of pipe. Twist a three-way connector onto each end of each of the two pipes, making sure that the orientation of the two connectors attached to a pipe is the same. Place the pipe onto a workbench or other flat surface to check that the connector positions match.

4. Apply a 1/2-inch wide band of PVC primer around each end of two remaining 5-foot lengths of pipe. Allow to dry for a few minutes, according to the manufacturer's recommendations.

5. Apply a 1/2-inch wide band of PVC cement around each end of the two remaining 5-foot lengths of pipe. Create a square base frame by inserting these two 5-foot lengths of pipe into the three-way connectors to join the four 5-foot lengths of pipe together. Make sure that the third, unused holes in the three-way connectors all face upward.

6. Apply a 1/2-inch wide band of PVC primer around each end of the two 10-foot lengths of pipe. Allow to dry for a few minutes, according to the manufacturer's recommendations.

7. Apply a 1/2-inch wide band of PVC cement around each end of the two 10-foot lengths of pipe. Create an arched upper frame by inserting each end of the 10-foot lengths of pipe into the unused, upward-facing holes of the three-way connectors attached to the base frame.

8. Allow to dry thoroughly, according to the PVC cement manufacturer's recommendations.

Cover the PVC Frame

1. Cut a 12-by-6-foot piece of plastic sheeting. Attach the shorter edge of the plastic sheeting to one side of the base frame so that the sheeting hangs approximately six inches past each end of the frame. Wrap the plastic around the frame, make a small slit near the PVC pipe and attach the plastic securely with several zip ties.

2. Stretch the plastic sheeting over the arched PVC pipe upper frame, wrap the end of the plastic around the PVC pipe on the other side of the base frame and secure with zip ties.

3. Wrap the loose ends of the plastic sheeting around the arched PVC pipes of the upper frames and secure with zip ties to finish the upper canopy. Trim any excess plastic sheeting.

4. Cut two 6-by-6-foot pieces of plastic sheeting to cover the ends of the cold frame. Attach the center side of each end piece to the arched frame with a zip tie on each side at a point approximately halfway down the arch.

5. Roll the edges of the plastic end pieces under and attach the plastic end covers to the top of the arched PVC pipes with several zip ties -- roll the plastic sheeting so that it fits the contours of the arched frame without trimming. Leave the bottom of the end pieces open to allow easy access to plants.

Tips & Warnings

• Place your cold frame in a sunny location so that it receives adequate sunlight for warmth and plant growth.

References

• Pond Plant Girl: Cold Frames and Greenhouses
• The Westside Gardener: How to Build a PVC Hoophouse for Your Garden
• Backwoods Home Magazine: PVC Pipe in the Home, Garden, Farm and Workshop