Cannabis Seedlings Phase: How to Take Care of Your Seedlings

Cannabis Seedlings Phase: How to Take Care of Your Seedlings

When growing your cannabis seedlings, it is essential to provide the right conditions to keep your plants growing healthy and strong. At the fragile seedling stage, cannabis seedlings are at their most vulnerable and need lots of TLC.


When the seedlings start growing, you will notice the “cotyledons”. These are two small round leaves that are typically formed in the seed. When the seed sprouts, the cotyledons emerge and start to grow from the center.


As the leaves grow older, they develop the familiar serrated edges common to cannabis plants. The seedlings thrive in moist conditions. At this stage, common mistakes occur that may deter growth and lead to life-threatening conditions.

Cannabis seedlings have particular needs to determine survival. Factors such as temperature, humidity, and light all have a significant impact on the seedlings. To help your plants flourish, optimize growth conditions by meeting the growth essentials;


One of the most important factors to consider is the container in which your seedling will grow. A container that has too little space may lead to serious problems for your seedling. The container must have enough room for the seedling’s root system to develop and absorb sufficient water from the soil.


The container should also have drainage holes to prevent excess water accumulation. Excess water overwhelms the roots and prevents adequate absorption of water and nutrients from the soil.


Cannabis Seedlings Phase: How to Take Care of Your Seedlings
The goal of watering is to keep the medium moist, not flooded.
Photo Credits: Wikimedia Commons


Watering your seedlings is a crucial factor. Too much water can lead to waterlogging and hinder proper growth. At the early stages, cannabis seedlings do not have an intricate root system, so they do not need much water.

Misting your plant once or twice a day keeps the soil damp and gives the plant plenty of hydration. Remember to only water around the stem.

Grow Medium

Cannabis seedlings perform well in well-aerated, slightly acidic soil. At the seedling stage, your plant is sensitive to nutrients, and growing it in nutrient-rich soil will lead to nutrient-toxicity, which overwhelms the plant.


When your seedling has grown 3-5 sets of true leaves, you can gradually feed it under close observation.


Optimizing the temperature is vital for the healthy growth of your seedling. High temperatures above 80 degrees Fahrenheit will stress the plant and lead to stunted growth, while low temperatures will likely freeze the plant and affect its ability to absorb and use nutrients.


If it’s too hot, your plant will display signs of heat-stress such as curled up leaves forming a cup shape.


Cannabis seedlings are also extremely sensitive to light. Strong lights will burn the leaves or lead to crinkled leaves while insufficient lighting will lead to a lanky plant with a tall stem and not enough leaves. The plant may also be unable to stay upright and will eventually topple over.


To fix a cannabis seedling suffering from insufficient light, simply expose the plant to more light. I recommend using grow lights if planting your seedlings indoors.


At the seedling stage, you should keep the humidity at 70 percent. At such high humidity, the seedling can utilize the moisture content in the air to spur its growth without the need for overwatering the roots.

Common Mistakes to Watch out For When Growing Cannabis Seedlings

In addition to creating a perfectly optimized environment for your seedlings to thrive, it is also important to know common mistakes you might make and how to correct them. Remember, it is essential to watch your plant carefully for any signs of suboptimal development.

Hot soil

Hot soil is a growth medium with too many nutrients. As earlier discussed, such a medium can cause nutrient burn. Cannabis seedlings suffering from nutrient burn display a dark green color with burnt tips.


Luckily, your plant can still be saved. You can remedy this condition by watering the plants adequately and withholding the nutrients for some time. When fully recovered, start the nutrient application with half the recommended dose of nutrients and gradually increase as you observe the plant for any reactions.

Nutrient Deficiency

While you do not need to add nutrients during the early stages of seedling germination, you should watch for nutrient deficiencies. If you’re using a nutrient-rich medium, nutrient deficiency is unlikely to occur during the first few weeks.


However, if your medium has insufficient nutrients or the wrong nutrient combination, your plant will be emaciated in no time. Watch out for yellowing or folding on older leaves and adjust the nutrient levels appropriately to help your plant recover.

Light Deficiency

If you are growing your cannabis seedling outdoors, the all-powerful sun got you covered. It is also much easier because you never have to worry about too much sunlight. If it is hotter than usual, remember to mist your plant regularly to prevent it from drying out.


Growing your plant indoors means you have to keep a watchful eye on the lighting conditions. When marijuana plants reach light saturation, their growth rate slows down. However, pushing away the source of light quickly resolves this problem. Keep your plant 2-4 inches from the source of light and alternate between 18 hours on and 6 hours off for optimal growth.


You can spot light deficiency if your plant is too tall with leaves that grow only at the top of the stem. You can remedy light deficiency by improving light exposure.

Watering Problems

Your seedlings need water to thrive, but overwatering will keep them drowning— inhibiting airflow to the roots and nutrient absorption. Overwatered leaves will be bloated, fat, and droopy.

To avoid overwatering, always keep the grow medium moist and damp— not flowing with water. The goal is to nourish the seedling, not creating a pond of your grow medium.

Underwatering is also common among novice growers. When underwatered, the leaves will become thin and begin to wilt if you don’t remedy the problem early enough.

Cannabis Seedlings Phase: How to Take Care of Your Seedlings
Choosing the right grow pot is essential in solving water problems.
Image credits: Wikimedia Commons

To prevent underwatering, choose the right container with enough drainage. A pot that is too big for the seedling will drown the roots and prevent the plant from absorbing sufficient oxygen. On the other hand, a too small pot can cause the root system to tangle up, inhibiting water, and oxygen absorption.

In Conclusion

The dream of a bumper harvest begins with seedling care. From germination to vegging, there’s a lot to do— and doing it right is essential for your overall weed-growing goal— getting ‘em frosty nugs! This article will help you along the way.