The early gardener harvests the larger tomatoes. If you want to benefit from this experience, grow your paradise apples in the cold frame. This gives the young plants a real growth advantage for planting outdoors. This guide explains how to do it.
How do you grow tomatoes in a cold frame?
Growing tomatoes in the cold frame: Fill multi-pot plates with growing soil, place one seed in each pot and cover it with a maximum height of 5 mm. At 20°C, germination takes 8-12 days. Prick the seedlings into 10 cm pots when they have 3-4 leaves and keep them slightly moist until mid-May.
Sowing tomato seeds in the cold frame - How to do it right
If your cold frame has natural heating, the window for cultivation opens in February. We recommend sowing in multi-pot trays to ensure gentle handling of the young root balls. How to proceed step by step:
- Fill the pot with potting soil or a mix of vegetable soil and sand
- Press the multi-pot plate in the cold frame up to the edge into the warm soil
- Place a tomato seed in each individual pot and sift over it to a maximum height of 5 mm
Spray the substrate with room temperature, soft water and close the cover. At 20 degrees Celsius, germination takes 8 to 12 days. The higher the temperatures in the cold frame, the faster the process progresses. During this time, keep the seeds constantly slightly moist, as drought stress is now the greatest danger to your seedlings.
Professionally pricking and caring for it – this is how it works
The growth of two cotyledons signals that growing your tomatoes in the cold frame is successful. The seedlings are repotted into larger containers when they have 3 to 4 leaves at the earliest. The longer you delay the measure, the better prepared your young plants will be for this hardship. How to proceed professionally:
- Fill 10 cm pots with vegetable soil
- Create a small depression with a spoon or stick
- Carefully lift a young tomato out of the growing pot
Plant the seedlings so deeply that the fresh soil reaches just below the cotyledons. Press the substrate firmly and water. Keep your tomatoes slightly moist until mid-May and add a little liquid fertilizer to the irrigation water every 14 days. After the ice saints, the strong young plants take their place in the sunny garden bed.
Tip
The cold frame is not just reserved for growing tomatoes. Are you wondering what else can go into the mini greenhouse? Then combine growing tomatoes with spring onions. This means you can not only make optimal use of free space in the cold frame. In addition, onions in mixed culture ward off the dreaded pathogens of late blight and brown rot.
