Three methods for success with your own tomato seeds
Text & photo: Lars Lund
Tomato seeds are expensive, and should you manage to harvest them from a tomato, you will quickly get a lot of plants from a single tomato seed. But can you sow the seeds from a store-bought tomato? And how do you get the seeds to sprout?
If you prefer to buy your seeds, what kind should you look for? Are F1 seeds better than those that are not F1 seeds? And what are F1 seeds? All these questions will be answered in the video below (please accept cookies to watch the video).
Note that the video is in Danish, but it is possible to choose English subtitles in settings.
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Here are 6 tips for succes with tomatoes:
Early season tomatoes:
Cultivate early sorts that ripen in time.
See the time of harvesting on the back of the packaging.
A place with light, but not too warm:
Let the seeds germinate at 22-25 degrees Celsius. When they are germinating, place them somewhere that is approx. 18 degrees. The warmer it is, the more light they will need. Try to give them as much light as possible. You can also use artificial light in the morning and evening.
Water from the bottom:
When it starts to germinate, make sure that the roots are deep in the soil. You can do this by watering in the plant saucer instead of watering the soil. This is especially important when cultivating in beds. From the start the plant will learn that it has to get water further down in the ground. The further down the roots are, the fewer times you need to irrigate.
Plant the tomatoes deep in the soil especially those who have gotten tall and thin in your windowsill. Preferably so the stem is 10-15 cm down in the ground and covered with soil. The small hairs on the stem will grow new roots, which will grow from the stem below the ground. The stronger a root system, the healthier the plant.
Do not transplant too early:
Tomato plants can be transplanted in the start of May or later in the middle of May. Do not listen to those bragging about having early tomatoes in the greenhouse. The thing is, that they probably had to heat the greenhouse (which is expensive), and there is a chance that they will get problems later on with diseases due to transplanting the plants too soon.
If you no longer have space for your tomatoes indoor and you want to have them outdoor, they must be hardened first. You can do this by placing the plants outdoor during the day and take them indoor before it is night and it gets cold. When it is time to transplant the plants, the temperature in the greenhouse should preferably be 12 degrees during the day and at least 7 degrees at night. If the plant is not hardened, it can only tolerate temperatures down to 12 degrees at night. If the plant is transplanted too early without getting any extra heat, its root system will not develop properly. Therefore, if you transplant too soon, the plant will have a poor root system. The plant can survive like that for a while, but when it is time to grow and bear fruit, the buds may fall off and the plant can get diseases. So be patient when it comes to transplanting. If you buy the seedlings at a nursery or the supermarket, let them take care of the plants until they are ready.
When the tomato plant grows and it is time to nip off the side shoots, place the side shoots in some potting soil. Now you will get new and free plants!
If you do not know what seeds to get, you can get advice from your local nursery or garden centre. You can also find a wide selection of seeds online – including traditional and more rare tomato seeds.
Om Lars Lund
Danish horticulturist and journalist
Lars Lund has for many years engaged in the garden and greenhouse. Lars has published many books about greenhouses, and he has participated in many Danish horticultural TV shows. He is a walking garden encyclopaedia, and he has answers for most basic cultivation questions – also the more ambitious ones.
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