The first days and weeks of cultivation are very critical, and the success of the entire cultivation cycle depends on them. What we neglect in the beginning will be difficult to catch up with. Many growers are well aware of the difficulties we may encounter - seedlings wither, do not grow, lose color or perish completely. Let's look at what are the most common causes of failure.
Seedlings - Pre-cultivation and acclimatization
Seedlings are small plants grown directly from seed or obtained by cuttings. When growing from seed, growers usually pre-grow seedlings, because it is never certain how many seeds the seedlings will grow from. Even when germinating and pre-growing such seedlings, it is necessary to be careful and give the plants the highest level of care. As soon as the plants hatch above the surface of the growing medium, we try to get them used to the environment in which they will grow. If we intend to grow under artificial lighting, it is good to put them under a lamp as soon as possible. In the first days, we leave the lamp very high above the seedlings so that we do not burn them. Sufficient light should force the seedlings to grow stronger soon and not stretch to heights. If the lights are low, the stems are unnecessarily long and especially weak. This can result in low plant stability and easy breakage.
The first step to success is therefore to grow seedlings with a solid stem, which the second leaves begin to form low above the surface of the growing medium. Even when growing under the sun, it is advisable to pre-grow the seedlings inside and move them outside only when they are strong enough. Moving to the sun should be done gradually. Plants grown on the window are not used to the intense sunlight that awaits them outside. The sun could do a lot of damage to them. Therefore, it is good to protect the seedlings from the sun for the first few days, which means giving them shade at the time when the sun shines the most. After a few days, the plants form a natural film on the leaves, which protects them from intense radiation.
Once the seedlings grown from the seeds are well rooted in the medium in which they germinated and sprouted above the surface, we plant them in a place where they spend the rest of their lives. Each transplanting is a risk period, after which the plants need a few days to get used to the new environment, before they continue to grow. For this reason, we always try to reduce the number of plant transplants to a minimum. When growing outdoors, we sometimes have to transplant the plants twice, but that should be the maximum. If we damage the roots or the body of the plant during transplanting, we increase the risk of death of the seedlings. Proper timing of planting and careful handling of seedlings is another step in reducing the risk of death.
When growing from clones, it is also important to acclimatize them to the new environment. Cuttings usually take root in completely different light conditions than the ones in which we transplant them, both in the case of growing under artificial lighting and in growing in nature. If we put the clones under a high-pressure lamp, it is necessary to leave as much distance as possible between the seedlings and the lamp, as in the case of seedling seedlings. If we don't, the lamp could burn the seedlings. When grown outdoors, acclimatization takes place as described at the end of the second paragraph.
Irrigation and humidity
By far the most common reason for dying or stagnation of seedlings is inappropriate watering and poor climate, while irrigation is the most risky. When the plants are small, they cannot cope with any great stress. Excessive watering is a huge stress in such a case, as the roots do not have enough oxygen and the plants are unable to draw nutrients from the growing medium or nutrient solution.
Growers sometimes feel like giving the plants everything in a heap. That's why they fertilize them from an early age and water them profusely. But the plants don't need that. Excess nutrients would be difficult to consume under optimal conditions. If they also have a lot of water, their ability to consume nutrients is significantly eliminated. Such seedlings begin to wither and turn yellow. When the inexperienced gardener sees this, he thinks that the plants wither because they have little water, and he starts watering them even more. The logical outcome is complete inhibition of growth (the plant is drowned and its root system is almost destroyed), in the worst case, complete death of the plant. Therefore, if your seedlings turn yellow and have drooping leaves, first check the level of moisture in the growing medium. If the medium is completely dry, then it is really necessary to water the seedlings. However, if the medium is damp or wet, the seedlings are most likely overflowed, and the watering must be reduced or omitted for a few days.
The unsuitable climate is also related to the previous paragraph. Plants can draw a lot of moisture from the air. If we can provide them with high humidity, they do not need to be irrigated so often, because the medium does not dry out so quickly, and the plants do not draw as much moisture. And especially in the case of seedlings, this fact is a great benefit. When growing in a greenhouse or under artificial lighting, we can also increase the air humidity artificially and we should not neglect this possibility. Believe that seedlings grown in humid climates attach very quickly and grow much faster than seedlings grown in low humidity.
In conclusion, I will quickly summarize that the most common causes of seedling death are excessive watering, low humidity and too intense light. If you manage to control these three aspects, you have almost won. I wish you good luck.