How to Solve Problems with Marijuana Seedlings After Germinating Seeds

The time has finally come for the germination of your cannabis seeds. Once the embryo has emerged from its protective shell, the young marijuana seedlings begin to develop their first leaves and a stem that is still weak. It is during these initial stages that they are especially sensitive: the shoots need special care to prevent damage caused by agents such as rain, wind, and fungi.

Just like with newborn animals, newly sprouted plants are much more sensitive to external threats than adults. So it’s necessary to make an effort to protect them from any dangers. And since we’re in full germination mode, it’s time to devote all our care and attention to those delicate shoots that in a few months will become tall, healthy plants.

The process begins with the cracking of the seed, caused by the expansion of the embryo, which pushes through the split in the seed’s two lobes, freeing a weak, primordial stem. Once in the growing medium, it buries itself to form a tiny root that gradually grows stronger until it becomes vigorous enough to lift the remains of the seed to the soil surface. The first leaves, known as cotyledons, act like a pair of solar panels, capturing sunlight and producing chlorophyll to finally give way to the first serrated leaves.

These initial phases are crucial to ensure that the following stages of development go as expected. Therefore, we must be especially careful and consider all the factors that can harm newly emerging shoots. Temperature, water, oxygen levels, nutrients, and salts are some of the variables that require close monitoring. To make things easier for you, we’ve prepared a rundown of some of the most common external threats and possible solutions to protect your crops.

A Good Plant Grows in Good Soil

First off, make sure there’s proper drainage to prevent water from building up near the roots. To achieve this, you can add some perlite or vermiculite to your soil mix and avoid planting the sprouted seeds too deep in the container, since water tends to pool at the bottom. It also helps to sterilize your tools or spray the soil with an antifungal treatment (copper, chamomile, and garlic can work), as well as rake the soil and let it sit in the sun for a few days before planting if you’re growing directly outdoors.

Protection from Bad Weather

At this time of year, when the weather starts to be a bit more pleasant, you can take the seedlings outside for a few days after they’ve germinated so they can receive sunlight and rainwater. However, a downpour or a strong hailstorm—common in these months—can completely ruin them and undo all your earlier work.

Luckily, there are several ways to protect your seedlings from harsh weather, like setting up a small greenhouse or covering the pots with plastic or glass containers. A pretty simple solution would be to use plastic cups, jugs, or empty water bottles cut in half and secured to the ground. These artificial shells will not only shield your plants from water and hail but will also help maintain optimal humidity and temperature levels.

Outdoor growers who are up for a bit more of a challenge can build a small greenhouse to shelter their plants. There are different ways to do this, depending on your preferences, budget, and what materials you have available. One option is to build a rectangular frame: wooden slats joined with mosquito nets or metal mesh for the sides, and a stronger material like plastic or glass for the top. This way, the seedlings get proper airflow and are protected from spring storms.

Barriers Against Insects and Pests

In addition to the weather, your tiny plants can also be attacked by animals like birds or lizards, as well as larger insects that can damage them before they fully develop.

To keep these critters away, use the greenhouse setup we described earlier or a triangular frame lined with metal mesh, like a small tent. Repurposing an item made of this material, like a wastebasket, is also a great idea. And if you want to add extra protection from the rain, all you need to do is cover the entire frame with plastic.

Avoid Overwatering

Even if you’re growing indoors, small plants may show signs of overwatering. During the early growth stages, plant roots are still very small, so their absorption capacity is much more limited than in mature plants.

There are two situations—besides having poor soil or a container with bad drainage—that often lead to water buildup: either the container is too large and holds more water than the plant can absorb, or it’s too small and doesn’t leave room for proper drainage once the plant starts growing. Both problems can be solved by choosing the right container size and transplanting the seedling before the original pot becomes too cramped.

Long, Thin, and Weak Seedlings

One way to strengthen plant stems is to gently bend them forward and backward. Although this might seem stressful for the plant, the movement causes micro-fractures in the stem tissue, which triggers the plant to rebuild it stronger. Another method is to make sure the plant gets a high dose of blue light (red and orange light can cause the stem to stretch too much), keep the temperature around 79°F (26°C), and provide the plant with plenty of light and airflow.

Wild cannabis plants develop strong stems by swaying gently in the breeze. This airflow is essential for good structural integrity. However, overly powerful ventilation can actually knock them over, causing bends in the stems that prevent them from standing upright again.

To avoid this, place a household oscillating fan near the seedlings and set it to the lowest airflow, directing the breeze toward the plant canopy. Staking the seedlings with a small stick and tying them with a string can also give them some extra support so they don’t get knocked over by the wind.

As you can see, you don’t need to be an expert to achieve healthy and robust germination, though it will require some attention and time. Tiny cannabis seedlings need your care in order to grow strong and healthy.