Why Have a Cold Frame? It Extends the Garden Season!
A cold frame helps keep plants warm from late winter until late autumn. Some plants can even overwinter in a cold frame. However, extending the growing season is far from the only advantage that a cold frame brings to your garden. In a cold frame, you can force vegetables, grow quality seedlings for later outdoor planting, or directly grow heat-loving vegetable varieties during summer. A cold frame can function as a simplified and cheaper version of a greenhouse. In winter, you can store some types of harvested vegetables in the cold frame for gradual consumption during the cold months.
For enthusiastic and active gardeners, a cold frame is an obvious choice
If you need to try everything in your garden, grow your own seedlings, and want to harvest vegetables for as long as possible, start building right away. Anyone who can easily get hold of a pile of manure will have it much easier. On the other hand, if you prefer to buy seedlings from a garden center and feel relieved after autumn digging that you have peace for half a year, then you probably won't make much use of a cold frame.
How to build a cold frame?
You probably know what a cold frame looks like. The cold frame consists of a box-like structure covered from above with glass or plastic sheeting. The frame is about 10 cm higher on the north side than on the south side; the slope is important for water drainage and light exposure. The ideal orientation for a cold frame is from west to east. If you're building the cold frame yourself, the bottom frame is best made from wood (don't forget proper treatment against moisture), but it can also be made from other materials. You can also buy ready-made frames. You can make a glass cover from an old window, or attach transparent horticultural film to a wooden frame of suitable dimensions. Cold frames in the form of mini greenhouses are also made from transparent polycarbonate.
A cold frame is a relatively simple device, but when setting it up, you need to follow the correct procedure to ensure it works as effectively as possible. Start by digging a pit about 30 cm deep, with dimensions matching your future cold frame. The lower frame of the cold frame will be set at the same depth. First, place a layer of leaves at the bottom, followed ideally by horse manure with straw (alternatively rabbit or sheep manure, which should be left in a pile for a few days beforehand to start heating up), then another layer of leaves on top. The layered material should now approximately match the surrounding terrain level - tamp everything down as you go. Now add about 20 cm of sifted humus-rich soil or compost and you're done. Caring for plants in a cold frame requires some experience. You'll need to use a ventilation peg to regulate air exchange, occasionally provide shade for the seedlings, cover the cold frame with matting on cold days, etc. Talk to a more experienced neighbor or contact Pěstík, who will be happy to answer any questions you may have.
Simpler Alternatives to Traditional Cold Frames
White non-woven fabric can help protect your spring sowings from frost to some extent - simply cover your beds with it. Using pegs and frames, you can create a portable protective cover from the fabric. You can also use plastic film covers and tunnels for the same purpose.
Cold Frame on Your Windowsill
You can also experience some of the benefits of a cold frame at home on your windowsill. A mini cold frame is useful for pre-growing seedlings, ensuring optimal humidity and stable air temperature for your plants. Which one should you choose? Browse through Pěstík's selection - from narrower, longer mini cold frames suitable for narrow windowsills to models with nearly thirty spaces equipped with peat growing tablets. Some types also feature practical ventilation openings with adjustable controls.