How to Build a Cold Frame with Used Windows

If you want to lengthen your growing season, one great way is to build a cold frame. A cold frame is simply like creating a miniature green house. Here are instructions on how to build a simple cold frame that sits over existing plants.

Difficulty: Easy

Instructions

1. 
    
   Old window

   The easiest and least expensive way to build a cold frame is to use an old window. This saves one more item from the trash heap and puts it to work.

2. The concept is to build a structure like a box with a tilted glass top and no bottom. This is an adaptation of the standard cold frame that can be placed directly in the garden to cover existing plants to extend their growing season. It is ideal to use for vegetables. And if you leave it in place over the winter, the soil will warm faster and you can then use it to start spring seeds earlier than weather would ordinarily permit.

3. Build two frames the same size as the frame of your used window. I suggest using 2 x 2 wood and stainless steel screws. (For a stronger frame use 2 x 4 wood for the bottom frame.) Using cedar or redwood will last longer than pine.

4. 
    

   Then connect the two frames with legs, the front legs being slightly shorter than the rear ones so the top will slope forward somewhat.

5. The sides should be covered with redwood or cedar, leaving the bottom open so the whole frame can be set over plants that are already growing.

6. 
    
   Hooks on the front

   Lay the used window over the top and attach with hinges on the back (the higher side). If winds are likely to blow your window top open, you can add a simple hook and eye closure in the front.

7. 
    
   Supports can also be on the outside of the frame if the window overlaps the sides.

   Since sun can warm the cold frame too much on warmer days, you will want to be able to open the top partially and leave it that way. You can add very simple supports in the way of 1 x 1" pieces held by a single screw on either side of the box on the inside. These can be swiveled up to prop up the frame. There are a lot of other ways to prop it open. Just use your imagination.

8. This is just one way to build a rudimentary cold frame. If you want yours portable, keep it small and build more frames to cover more space. If you want to leave it in place (and remove the window top so it stays all year) then you can build it any size. With the cost of food and cut flowers, extending your growing season not only adds more time for gardening fun, but can save money, too!

Resources

• Gates & Croft Horticultural Design ideas and info

[momandpopoften]

on 10/27/2008 Any ideas on where to get old windows?

[HairCrazy]

on 10/27/2008 Great ideas. Thanks!