Building A Coldframe

Building a coldframe can be fun and easy if you follow these simple instructions.

Coldframes will increase the possibilities of gardening and add much to the enjoyment you'll have while using the coldframe. Now if you decide to build a coldframe you will need to consider where it is to be placed and how you are going to construst the frame.

If at all possible, it would be best to place the coldframe near the garden, provide ample space for it also. If the plants are to be grown well the rames must be where full sun can reach them and, if possible, the frame should have the protection of trees or buildings from the north. Good surface drainage is another great advantage. When you choose the site, it should be dug out to the depth of l8 inches, then filled in with six inches of cinders covered by a two-inch layer of coarse leaves to prevent top soil from sifting down into the cinders. Six inches of field soil are added and finally, three inches of finely sifted compost or potting soil. After this has been watered it will settle somewheat. The surface of the soil should be eight inches from the glass at its lowest point.

Now when you are making the coldframe, durability is an important factor. Wood is usually used and if you will buy the two inch lumber instead of the one inch it will be stronger and last longer. Cypress is the best wood if it is available. You will need to add a coat of creosote to make it last longer.



The inside depth of the frame should be determined by the height of the plants to be grown. If it is to be used for spring annuals, perennial seedlings or low stock that is to be wintered over, a 12-inch backboard and an eight-inch front board are sufficient. To grow most potted plants, 15 inches is the minimum height for the frame board and 18 inches for the back board. A standard glass frame sash is 3'x 6'. Therefore, when making a two-sash frame with an eight-inch-high front board and a 12 inch high back boardds, you would need to order these boards in six-foot one and one-half inch lengths.

The additional inch and one-half allows for a one-inch runner between the sashes in the center. Twelve-inch boards are used for the sides, graduated to fit the eight-inch height of the front board.

To the outside of the side boards, a two-inch-wide strip of wood is nailed the length of the boards, one inch below the top. This strip projects one inch above the side boards and acts as a guide when the sashes are pulled on and off. The corners of the frame are then nailed securely.

You will need to put runners to be able to slide the sashes up and down, these may be made of T iron sunk into the top edge of the front and back boards, and screwed in place. Then, a l" x 2" strip is extended along the center of the bearer to act as the center runner guide for the sashes.

Before placing the 1" x 2" runner on the bearer,

however, the two sashes should be in position, allowing 1 1/2" between the ssashes, then the inch-wide runner is nailed in the center. This allows one-quarter inch clearance for each sash from the runn, thus preventing binding in damp weather.

To prevent the frame from spreading from the inside, two 2" x 2" stakes are driven into the ground outside the frame; one at the center of the back board, the other at the center of the front board. They are cut off flush with the top of each (12 inches high for the one at the back, and eight inches for the one at the front), then nailed securely to the frame. Earth banked up about six inches high against the outside of the frame will accomplish the same purpose.

© High Speed Ventures 2011