Using a cold frame to protect and grow garden plants can give you a head start on the growing season. Building a cold frame is relatively inexpensive and with a little work can make a great addition to any size garden. Using a cold frame can also give you fresh herbs and greens thru the colder months when it is not possible to grow them outdoors.
One key thing to consider when planning your cold frame project is the location. You will want to choose a location that takes full advantage of the available sun thru the cold months. The southern face of most buildings will provide the best sun in the winter months. To reduce the exposure to wind and weather conditions, locate the frame against a structure such as a house, barn, or fence. In addition, if the frame is against a heated building it will gather some heat from the structure. You will also want to incorporate some way of venting the top for the days when the temperatures get warmer as a way to regulate the temperature inside. Adding a thermometer is also a good idea to monitor the inside temperature.
Make sure to pick a spot that will drain well. Your plants will not do well if they are sitting in water for the time they are in the frame. Consider building a mound or slightly sloped area for your frame to sit on to maximize the drainage.
Most cold frames can be built from materials readily available. A popular way to make the glass top is to use old windows. These used windows can be obtained from construction salvage yards, family members, and on the internet. You can use any clear or translucent plastic material for the top also. Most hardware or discount home supply stores can cut the sheets to the size you need at a reasonable cost. Remember that your cold frame will be out in the bad weather so chose the material for the sides and back accordingly. Many woods such as Cedar or Cypress are naturally resistant to weather and rot. Also there is a wide variety of recycled construction products available to use. I do recommend staying away from treated lumber as a material because of the possibility of chemicals leeching into the ground around you new plants. It is good to remember anything that goes into the soil has the potential to end up in your plants. Use anodized or some form of outdoor hinges and fasteners to put it all together. This will keep the hinges and latches working all year and the screws from rusting which leaves an unsightly brown streak on you cold frame. You can decorate or paint this to your taste or to match your outdoor design of the space it is in.
Here are a couple more tips to help make your early growing season a success. When the mercury dips down into the low temperatures, cover your cold frame with a few blankets, doing this will keep the plants inside nice and cozy. On the other end, when the sun is out and the thermometer rises, open it up and give them some fresh air. Use your creativity and an internet search, and you can come up with a great plan to start your gardening year off right. Good luck and happy planting.
