How To Care For Your Weed Seedlings

The seedling stage can be an especially vulnerable time in the growing process. The cannabis seedling is in need of a lot of TLC to grow into a healthy cannabis plant.

This article discusses how to support young seedlings so that they grow into strong high-yield plants. If you want to have an optimal harvest at the end of your growing season, then you need to take great care of your marijuana plants during every stage of their life — not just at the end, when the harvest is upcoming. Arguably the most important stage of a marijuana plant’s life, the seedling stage is the time when your plants are most vulnerable. A healthy seedling stage in your marijuana plant’s life will mean a strong foundation for vegetation and blooming growth later on.

When sourcing your seeds, be sure to actively search out the right strain for you; your experience and skill as a grower, budget, grow equipment, preferences in taste and effect, and whether you’re growing indoors or outdoors will determine which strain will yield the best results for you.

Since marijuana plants are at their most vulnerable during the seedling stage, it is of the utmost importance that you go to great lengths to preserve their safety. Think of it as an investment for the future vegetation phase, as well as your final harvest. The safety of your seedlings is less about the risk of them being discovered, and more about them facing other sorts of risks.

Insects, rodents, and other pests will be very interested in eating (and therefore destroying) your seedlings. You should therefore use some sort of shelter to keep these pests out — a transparent bubble or dome of some sort should do the trick. Many growers prefer to make these shelters themselves by using clear plastic bottles that they cut in half, and use the lower half to place over each seedling. Don’t forget to cut holes in it for proper ventilation. This dome will both protect your young marijuana plants from pests, and also from the threat of an unexpected frost, serving as an effective insulator.

While your seedlings require protection from certain things, they need a lot of other elements, like sunlight and water, for example. The soil around your seedlings should always be moist, and there should be lots of sunlight available to them. The difficulty or ease of accomplishing this may depend on where exactly you live. Climates located further north, for example, have shorter spring days and therefore less sunlight. If your seedlings are not receiving enough sunlight, they will begin stretching vertically until they are too tall to stay erect. You should avoid this from occurring at all costs.

For this reason, (among others), many growers opt to have their marijuana seeds sprout from inside an indoor controlled environment, such as a closet. You can use artificial lights to provide your seedlings with the nutrition they need to get a healthy, strong start to their lives. This, of course, also carries the burden of needing to transplant your plants later on, so you should weigh your options carefully before deciding which one to go with.

How to water your seedlings

The most common issue with watering seedlings is actually overwatering them, especially when it’s your first time taking care of marijuana seedlings. In this case it is not actually the quantity of water that is the problem, but rather the lack of oxygen due to the large amount of water. This occurs most commonly in plants that are growing in containers.

Drooping leaves form one of the most easily recognized symptoms of overwatering. If you see this happen, you need to take action.

Nutrients for seedlings

You have to be careful when feeding your seedlings nutrients, as the development of a nutrient toxicity is a serious and potentially devastating issue for young marijuana plants. If you grow your seedlings in soil that is “hot,” or nutrient-filled, then you can compensate for it by adding extra water. Whatever you do, avoid using “slow-release” soils, including Miracle-Gro. These soils will cause your seedlings to be at a higher risk for nutrient toxicity.

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In general, it isn’t a good idea to give young seedlings too much in the way of nutrients. A high quality potting mix should do the trick, even without any added nutrients, until your seedlings are at least a few weeks old.

On the other side of the spectrum, it’s also possible to give your seedlings less than they need. This is called a nutrient deficiency. If, for example, you purchased the wrong kind of potting soil for marijuana seedlings, it’s possible they could end up with a nutrient deficiency. You will be able to tell if that is indeed the problem from the leaves, which will begin folding and turning yellow. Those leaves will, over time, wilt and fall off.

For this reason, it is important to ensure that your plants have the right quantity of nutrients throughout their lives, especially when they “use up” their soil. Plants grown without soil also require nutrients.

Another perpetrator of nutrient issues in your seedlings could be an unbalanced pH level. A pH level that isn’t balanced could even prevent your plants from absorbing the right amount of nutrients, even when those nutrients are plentiful within the soil.

Temperature for seedlings

In general, the perfect temperature for growing healthy seedlings is right around 73 degrees Fahrenheit. Anything higher than that will cause the leaves to begin to curl up. And should they curl, you can solve that problem by simply lowering the heat, or moving the lamp further away from the plants. If combined with underwatering, this could have a drastic effect on your young marijuana plants.

Light for seedlings

For indoor-germinated seeds, keep your seedlings under fluorescent lighting, as they are energy efficient and also don’t create much in the way of excess heat. They can safely be located just two to four inches away from your plants. Give your seedlings light in intervals of 18 hours of light, and 6 hours of dark.

For seeds germinated outdoors, you will be depending on the sunlight. In general, you won’t exceed your plants’ sunlight “limits” unless you neglect other aspects of their care. If your seedlings are beginning to grow taller and skinnier, they are “stretching” to reach more light — that means they don’t have enough as it is.

Simply put, if your seedlings are stretching out, this is a problem. They need to have sturdy, strong stems to support the vegetative and flowering phases later on, so a stretched out seedling will be counterproductive. If your seedlings do begin stretching out, try bending the stem back and forth in order to force it to “rebuild” the spots that have bent and torn, therefore leading to an overall sturdier stem. If you’re able to, provide the plants with more light to avoid this problem altogether.

[Updated, originally published 5.11. 2017]

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