Every gardener’s season starts with seedling cultivation. Although harsh frosts are still common outside at this time of the year, serious work can already begin indoors or in a heated greenhouse. Planting is one of the key steps to successful vegetable production. Healthy, resilient seedlings can lay the foundations for a successful growing season.
However, if mistakes are made during seedling establishment and the plants are exposed to disease or stress, it can lead to serious economic losses during the season. It is clear that gardeners need to pay special attention to this process. With Biomit technology, however, we can greatly increase the chances of success and avoid serious plant diseases or physiological problems.
What is seedling cultivation, and which plants are grown as seedlings?
The goal of seedling cultivation is to grow plants under controlled conditions, ensuring they are more resistant to external environmental factors after planted outside once the frost has passed, and are more likely to root and start to bear fruit compared to the ones that were sown directly. It is also important that the successfully grown, healthy seedlings are no longer threatened by diseases or pests like those that were sown directly.
Long-lived, frost-sensitive plants such as peppers (especially chillies), eggplants and tomatoes should be grown as seedlings. This will allow the seedlings to ripen sooner and harvest until the end of the season.
Vegetables with a medium growing season such as okra, chard, kohlrabi or basil, can also be grown successfully by planting the seed directly in the open ground. The same is true for vegetables with a short emergence and short growing season, such as lettuce, courgettes or cucumbers.
The process of growing seedlings.
There are 5 important stages in seedling establishment:
- Germination: This starts with seed sowing and continues until the seeds germinate. Its duration depends on the plant and the environmental conditions.
- Development of petiole.
- Appearance of the first lobes.
- Seedling development.
- Seedling training, transplanting.
Plants need different care at different stages. The good news is that with Biomit technology, we can help our plants grow as successfully as possible at each stage.
Preparations
Before starting to grow seedlings, it’s advisable to get the materials you will need. Before making any purchases, make a plan for how many plants you want to grow, how much space you have available, and where you will transplant the fully grown seedlings. Afterward, it’ time to buy the planting medium. For this purpose, we recommend using potting soil. This contains the right proportion of nutrients that the growing plant will need. It also has a sufficiently loose structure that allows developing, tiny roots to penetrate.
More advanced growers can mix their own potting soil. For this, you’ll need approximately 20% garden soil, 40% compost, 20% river sand for looseness, and 20% peat or coir to enhance water retention.
It’s important to know that in order to set up the right microbiome, it is advisable to water the mixture with Biomit Terra. This nutrient solution contains the beneficial strains of bacteria that are needed for the development of good soil life. In addition, the bacterial strains in Biomit Terra also kill pathogenic bacteria and fungi that may be present in garden soil. The roots of young plants can thus grow in a rich and beneficial microbial environment and are protected against fungal and bacterial pests that can infect the soil. Optimally, add 1 decilitre of Biomit Terra to 1 liter of water and use this mixture to water the growing medium.
Sowing and germination
The optimal time for sowing seeds should be adapted to the life cycle of the crop to be grown. The growing period determines how long each plant species needs from emergence to flowering, fruit setting and ripening. The garden vegetables with the longest growing period typically come from the pepper family. Chilli peppers, especially the extra hot varieties, are very slow-growing. The Carolina Reaper or Trinidad Moruga Scorpion peppers may require up to 150-180 days to go from the germination phase to the ripening phrase. Therefore, these plants should be sown indoors very early, as early as the end of January. This way, they will be strong and resistant seedlings when planted in mid-May.
Seeds of tomatoes, basil and classic peppers are also recommended to be sown by mid-March at the latest. Seeds of faster-growing crops such as kale, cauliflower, melons or courgettes can be sown as late as the end of March or early April, and seedlings ready for planting will develop by May.
For germination, the seeds should be placed in loose soil and the soil should always be kept slightly moist, but not muddy or stagnant. It is easy to check the correct soil moisture level by gently pressing the soil surface with your fingertips. When it feels sufficiently plastic and light, but no mud sticks to your hands, the moisture content is optimal. It is also important to ensure a minimum temperature of 28°C at germination. Light is not needed at the time of germination, so you can even keep the germinator in the dark.
Rising and the dicotyledonous state
After emergence, we can observe that the young plants produce two leaves that look exactly alike. This is the dicotyledonous stage. The majority of vegetables belong to the so-called dicotyledonous plants, i.e. two small cotyledon leaves appear after emergence. For the first few days, the plant nourishes itself from the cotyledons. In this stage, reduce the temperature to 22-24°C. At this time, however, the sprouted plants should be placed in a light-rich environment. It may be useful to supplement with additional lighting.
Pricking out
If the seedlings are too dense after germination, it’s advisable to prick them out. This is particularly important for tomato, pepper, and eggplant seedlings. At this point, the individual plants should be transplanted into separate pots. This will provide them with sufficient space for both their roots and green parts to develop properly. Before spiking, fill the pots with potting soil or your own mix mentioned earlier.
Before transplanting the young plants, water them well so that the fine hair roots are easy to free from the soil. Use a sharp knife to cut the soild around the plant, then, if possible, lift the seedling out using a blunt, flat tool or spatula. The most ideal size is a 7×7 cm pot, into which the seedlings should be placed one by one.
Raising and hardening seedlings
The most important task after pricking out is to get the seedlings in the best possible condition for planting outside (which is typically the second half of May in temperate climates, when the risk of ground frost has already passed). During seedling cultivation, it is important that the plants receive as much light as possible, as in low-light environments, the seedlings tend to become leggy, with weak stems that won’t support the weight of the plant. The temperature should be gradually reduced to prevent the development of fungal diseases and improve the plant’s resistance and immune system.
One of the most dangerous diseases of young seedlings is damping-off, a symptom complex caused by various pathogenic fungi. When it appears, a brownish discolouration develops on the root neck of the seedling, followed by thinning of the lower part of the stem, the plant tilting and eventually dying. This disease can destroy the entire stand when the plant is in seedling stage, so it is advisable to control it continuously. This can be done with a 10% solution of Biomit Terra. Dissolve one decilitre of Biomit Terra in 1 litre of water and water the seedlings with this mixture every 2-3 weeks. Be cautious, and rather apply in small doses several times a day to avoid the soil becoming stale. Biomit Terra contains beneficial bacteria that successfully fight off pathogenic fungi and bacteria present in the soil.
Planting
The optimal time for transplanting seedlings is when they have 6-8 true leaves. If less developed seedlings are planted, it increases the risk of seedling mortality. The typical planting time is in the second half of May, after the risk of frost has passed. It’s important to keep in mind that transplanting is a significant stressor for the plant. Compared to the controlled conditions, the seedlings will face many more negative factors in the open field. Therefore, it is advisable to gradually acclimate them to outdoor conditions by taking them outside for shorter periods in the week or two before planting, or if this isn’t possible, reducing the temperature. The plants should be placed in well-prepared soil with a loose, friable texture. The soil microbiome is key to the successful rooting and development of seedlings.
Before planting, irrigate the trench or planting hole with Biomit Terra and Biomit Genesis (1 litre of product per 10 litres of water) to promote rooting and the development of microbial root-fungus relationships.
Planted seedlings can also immediately provide fresh food for pests, so it’s advisable to be prepared for control. After planting, the stock should be foliar fertilised with Biomit plant conditioner.
This product repels sucking and chewing pests, such as aphids or leafhoppers, with its fragrance. The micron-sized ground dolomite it contains creates reliable protection on the plant’s surface.
If you want to become a successful vegetable grower, contact our expert consultant and request a detailed treatment plan tailored to your specific crop.
