Cold Frame

Make your Own Cold Frame

Cold Frame

Grow all year round with this simple cold frame made from plywood and an old wooden window. Place your young or sensitive plants inside to keep them warm during the winter months. You can either fill the box with growing medium and use it as a raised planter, or you can place other pots or containers in it for cold weather. On hot days, prop the window ‘roof’ open to let the plants breathe and to keep the temperature down.

You’ll need:

A wooden window – we upcycled one that measures 1450m x 510mm. (Obviously you will need to adjust your measurements to the window that you use.)

12mm plywood cut to the following dimensions:

  • 1 x 1490mm x 495mm (base)
  • 2 x 500mm x 475mm (sides)
  • 1 x 1490mm x 300mm (front)
  • 1 x 1490mm x 500 (back)
  • 2 x 475mm x 30mm x 30mm (cleats)
  • 2 x 220mm x 30mm x 30mm (cleats)
  • 2 x 420mm x 30mm x 30mm (cleats)

A pack of 35mm wood screws

2 x hinges Paint or EcoWood wood sealer

Tools: Jigsaw, tape measure, pencil, paint brush, cordless drill and driver bit


1. Cut all the plywood to size. The two sides need to taper from 500mm at the back to 300mm at the front, and are 475mm wide. Mark these measurements and use a jigsaw for the cut.

2. Screw a 475mm cleat to the bottom edge of each side. Butting up to this cleat, screw a 220mm cleat to the short edge and a 420mm cleat to the long edge.

3. Join the back and the front to the cleats of one side and then the other.

4. Screw the base to the bottom cleat of the two sides.

5. Place the window on the top and attach it to the box using the hinges.

6. Seal the entire structure with paint or an exterior wood sealer like EcoWood.

The Gardener