Actually, in March it is still too cold in almost all regions to cultivate vegetables. Protected by a cold frame, however, you can already sow radishes or lettuce and harvest them soon. To build such a small greenhouse yourself, you don't have to be a passionate craftsman. With our instructions, even inexperienced users can easily do this.
Building a cold frame yourself is not that difficult
Kits from the specialist trade
These are available in a wide variety of designs and sizes. The simplest models consist of a steel frame that is covered with a foil. However, they are difficult to ventilate at higher temperatures and are therefore more suitable if you want to try cold frame culture first.
Ready-made constructions with a flap are more suitable. If you follow the assembly instructions, the small greenhouse is ready for use in less than an hour.
Build your own cold frame
Skilled hobby gardeners can also construct the cold frame themselves. A size of 150 by 100 centimeters has proven itself. This offers sufficient cultivation area and you can easily reach all parts of the cold frame.
material list
- Wooden planks or pressure-treated boards for the frame, tailored to the planned width and length.
- square boards
- Styrofoam panels, 2 centimeters thick
- screws and hinges
- sandpaper
- old windows or a frame construction with double-wall sheets
- cordless screwdriver
- saw
building instructions
Choose a sunny, south-facing spot and position the bed so that the sun falls fully on it. The north edge should be about 15 centimeters higher than the south edge because the slope means more sun rays hit the cover.
- Build a wooden box without a bottom from the wooden planks. The planks are firmly screwed to the square boards and the side boards are bevelled.
- Clean up the saw edges with sandpaper so that no splinters protrude.
- Insulate with the styrofoam plates.
- The roof consists of old windows. Alternatively, you can build a frame onto which you screw double-wall sheets or plant film.
- It is screwed onto the wooden case with stable hinges.
Bricks, which hold the cover in the desired tilted position, are suitable for ventilation. If the wind threatens, these serve as a weight.
Put the cold frame into operation
To keep the little plants nice and warm, you need natural heating:
- Dig a pit the size of the bed at the intended location. This should be a spade blade deep.
- Fill in a foot of not too wet horse manure.
- Put a two finger wide buffer layer of leaves over this. Moisten this well so that it can be compacted.
- Cover with a twenty centimeter thick layer of finely sifted earth.
The optimal germination temperature is generated within about ten days by the decomposition process. This allows you as early as March
- pick lettuce,
- Radish,
- Cress,
- early carrots
sowing. The cold frame is also suitable as a preliminary culture for cucumbers, tomatoes and peppers.
tips
If it gets cold again, put straw mats or spruce sticks on the lid of the small greenhouse to protect against frost.