With a cold frame, the gardening season extends across all four seasons. Built by yourself with a little craftsmanship, the protected conditions offer ideal conditions for growing and cultivating your ornamental and useful plants. This guide shows you how to plant a cold frame properly.
How do I plant a cold frame correctly?
Planting a cold frame professionally: Fill the cold frame with a mixture of horse manure, straw, garden soil and compost. Sow radishes, ice lettuce, spinach and kohlrabi in February/March, cauliflower, pumpkin, runner beans and tomatoes in April/May, broccoli, melons, peppers and eggplants in June/July, radishes, lamb's lettuce, radishes and leeks in August/September, and in October/November winter vegetables such as kale and winter lettuce.
Preparation work – This is how natural heating comes into the cold frame
With the following preparatory work, you can create a perfect microclimate in the cold frame that allows it to be used almost all year round. The trick is to have a balanced filling that acts as a natural heater. What you need is a mixture of equal parts horse manure and straw as well as garden soil and compost in a ratio of 3:1. How to do it right:
- Dig a 40 cm deep pit in the cold frame
- Pour the dung/straw mixture 20 cm deep into the pit and tamp it down
- Spread the soil/compost mix over it in a 20 cm high layer and work it into fine crumbs
Within a week of filling, a pleasant warmth has developed in the cold frame. This results from the decomposition of the filling material by hard-working microorganisms. If the lighting conditions improve from February/March, this year's gardening season can start, even if there is still snow.
Planting cold frames correctly – tips for your schedule
A cold frame with natural heating offers a wide range of possible uses. Here you can grow early and winter vegetables, prefer young plants that require warmth or cultivate sensitive summer plants. The following schedule would serve as a suggestion for your individual planting:
- February/March: Sowing radishes, ice lettuce, spinach and kohlrabi
- April/May: Prefer cauliflower, pumpkin, runner beans and tomatoes for later planting in the bed
- June/July: Sowing broccoli, growing melons, peppers or eggplants
- August/September: Sowing later radishes, lamb's lettuce, radishes and leeks
- October/November: Growing and harvesting winter vegetables, such as kale and winter lettuce
Of course, the cold frame is not exclusively reserved for growing crops. Here, cold-sensitive flowers and perennials find ideal conditions to secure a vital growth advantage after sowing before they are planted in the bed and on the balcony.
Rational planting technology saves time and effort – this is how it works
The exemplary schedule shows how versatile you can use a cold frame for planting. To ensure that sowing, cultivation and transplanting run smoothly, saves time and is gentle on plants, the following cultivation technique has proven itself well in practice:
- Sowing seeds in small individual pots or multi-pot plates
- Leave pre-grown or purchased young plants in the nursery pot on the windowsill
- Sink these containers in the cold frame up to the edge in the ground
Seedlings and young plants benefit from the warmth that prevails in the cold frame as a result of the continuous rotting. Take the fully grown plants and their pots out of the ground so that you can pot them up now and plant them outdoors. In the cold frame, the freed-up area is used for new crops.
Tip
If obtaining horse manure or cow dung is a difficult task, you can install natural heating in your cold frame in another way. A mixture of equal parts autumn leaves and garden and kitchen waste, enriched with horn meal, develops a pleasant warmth within 2 weeks.
