How to Take Care of Your Cannabis Seedling?


Although the seedling stage of cannabis is short, usually just 2-3 weeks, it is crucial to the entire cannabis cultivation process. If something goes wrong with your cannabis plant at this stage, nothing that follows will work out! How to take care of your cannabis seedlings? This guide delves into the intricacies of cannabis seedling care, providing cannabis seedling day-by-day insights and addressing common concerns. 

 Cannabis Seedling


What should you do during the seedling stage?

During the seedling stage, the hard, black husk that contains all the genetic information of your plant absorbs water and nutrients to germinate in a warm, humid environment. After water gets into the seed it begins to extend outward with white roots and digs deep into the soil. At the same time, your plant will also send out a bud to find light. The two cotyledons originally contained in the seed begin to appear, and then the first set of true leaves will grow.







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Key Factors for Successful Cannabis Seedling Germination

Optimal Environment Selection:

 Start by choosing the right container and growing medium for your cannabis plant. For the growing medium, choose soil with a pH between 6.3-6.5, which is slightly acidic, and adding the proper amount of perlite can make the soil more aerated and help with drainage.

To grow seedlings, you can use germination pots or some small plastic cups and transplant the seedlings into pots after they have developed their first set of true leaves—or plant them directly into their final pot if you don’t want to always transplant (although we don’t recommend this). Most strains fit in 3-gallon pots.


Discover How to Germinate a Cannabis Seed: A Step-by-Step Guide

1. Choose the Right Seeds
2. Prepare Paper Towels and Plates
3. Set Up a Heating Mat
4. Label Your Seeds
5. Add Water and Cover
6. Set the Heating Mat to Around 80-85°F
7. Cannabis Seeds Typically Sprout Within 1-3 Days


Factors Affecting Cannabis Seedling Health:

  1. Grow Lights:
    Young plants can’t handle high-intensity light, so you can use adjustable LED grow lights or other lower-wattage grow lights like fluorescents or incandescent bulbs. Plants at this stage need more blue light to provide energy for vegetative and stem growth. With the VIVOSUN AeroLight, you can adjust the intensity and spectrum of light, making it a great tool for all stages of growth.
  2. Nutrients:
    Excessive nutrients can cause your seedlings to suffer a nutrient burn. When your seedlings are just starting to grow in the first 1-2 weeks, choose light mixes to fertilize. After two weeks you can increase the fertilizer appropriately.
  3. pH Level:
    We advise you to maintain a soil pH between 6.3-6.5 and never exceed 7. This way your plants can fully absorb all the nutrients in your medium.
  4. Temperature and Humidity:
    Seedlings are sensitive to temperature and humidity: they prefer a warm and humid environment. Seedlings will thrive in an environment of 72 to 79 °F (22 to 26 °C), and 65 to 80% humidity.
  5. Proper Distance between Grow Lights and Plants:
    If you’re using low-intensity lights, you can start with a 4-inch distance. Then place your hand on top of the plant for 30 seconds, if it feels warm but not hot, that’s appropriate, if not, adjust the height of the light based on how lean feels.
  6. Aeration:
    Plant roots that are in contact with air are “air pruned,” meaning you reduce the chance of getting rootbound plants. While outdoor plants have more than enough room to spread out, plants in pots can get bound up quickly.
  7. Pot size:
    We don’t recommend putting seedlings in a very large pot as this makes it difficult to control the amount of water. Too little water will not penetrate all the soil, and too much can drown your seedlings. There is no problem in choosing a small pot, as long as you are willing to transplant it.


Note: How to choose a pot?

The best containers for growing cannabis are of course fabric grow bags. It is possible to grow cannabis by choosing cheap plastic pots, but you need to pay attention to the following points when choosing a pot:


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How to Water Your Cannabis Seedlings?

Seedlings have very small roots and don’t need a lot of water. If you can’t control the amount of water you’re giving to them well, pay attention to the changes in the growing medium in the pot when watering. Water until the growing medium is completely moist, but not overflowing. This is the right amount for each watering; watering your seedlings 1-2 times a day should provide enough water.


Caring for Cannabis Seedlings

Watering Techniques:

Seedlings have small roots and require careful watering. Moisturize the growing medium until it’s completely moist but not overflowing. Watering 1-2 times a day is usually sufficient.


Monitoring Growth:

Track your cannabis seedling day-by-day progress. Observe for signs such as cannabis seedling leaves curling down, yellowing, or any other potential issues. adjust care practices accordingly.

Cannabis seedling leaves curling down is often indicative of overwatering, which can lead to root suffocation and nutrient deficiencies. Ensure proper drainage and watering practices to promote healthy growth.

cannabis seedling leaves curling down

Transplanting Considerations:

While transplanting is essential for some, others might prefer direct planting into final pots. Choose a pot size that allows for easy water control, avoiding extremes. It is recommended to transplant when the seedlings have developed two sets of true leaves and a well-established root system, enabling them to adapt more effectively to their new environment.


Common Issues of Cannabis Germination and Remedies:


Exercise caution regarding overwatering, especially since seedlings have small roots. Monitor the moisture level of the growing medium closely and adjust the frequency of watering accordingly.

Lighting Problems:

Ensure the appropriate distance between the grow lights and seedlings. Adjust the intensity and spectrum of light to suit the plant’s growth stage. Typically, cannabis seedlings require 100-300 µmol/m²/s of light to be considered sufficient.

Ready to Build Your Own Grow Room at Home? 

» Grow Room Mastery: 3 Steps to Improve Weed Cultivation Environment


Wrap-up: How to Take Care of Your Cannabis Seedlings

The process of going from a seed to a plant is wonderful and magical—we witness the birth of life. I’m sure you must be very excited when you first grow a seedling, that’s where it all started. If you don’t do well at this stage, your growth will be off to a bad start. We have to be careful with these fragile little things, and planting always requires patience, doesn’t it?

If you have any questions, please don’t hesitate to reach out to us!

And be sure to check out our other blog posts for useful tips on becoming a great grower!

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