How to Germinate Cannabis Seeds – A Comprehensive Guide 2025

Did you know that you can legally grow weeds, also called cannabis or marijuana, at home?

Yes, if you are 21 years of age or older, you are permitted to grow up to three mature and three immature weed plants in your home. Medical users of 18 years and above can also grow up to six cannabis plants in their homes.

So, if you are of age and have got some cannabis seeds to cultivate, this guide to germinating cannabis seeds is for you. Below, we will break it down step-by-step how to germinate cannabis seeds at home. Read on.

How To Plant A Weed Seed: A Complete Guide To Cannabis Cultivation

Although weed can be grown from either a seed or a clone, this guide focuses on how to grow cannabis from seed. Let’s dive into the home-based weed planting details:

Step 1: Choose the right seed

If you have gotten some cannabis seeds already, you can proceed to the next step, but if not, make sure that you start with healthy, high-quality cannabis seeds.

Weeds are available in different species. Hence, their seeds are available in different colors and sizes. This makes it difficult to guess which seed type is the most viable. 

However, if you have a variety of cannabis seeds to choose from, choose dark, plump seeds with distinct tiger stripes. This type is known for doing well.

Step 2: Choose the right germination method

There are many germination methods for growing cannabis, which include the glass of water method, the wet paper towel method, planting directly into nutrient-rich soil, using stone wool blocks, and so on.

Glass Of Water Method

The glass of water method is a simple approach and may be ideal for beginner growers. Although it is less effective, it is still viable.

This method involves dropping the cannabis seed in a half-filled glass or bowl of water at a temperature of about 22°C (71°F). After about three to five days, the seeds should start to open, revealing tiny white tips. Wait a few more days for the roots to shoot out. 

While waiting, prepare soil pots for your newly germinating seeds. Make a small hole of about ten to 15mm depth in each pot – this is where you will place your seed. Make sure that the nutrient-rich soil is wet but not soaked. 

Once the roots extend to about one to two centimeters in length, carefully and slowly transfer the germinating seeds from the water to the well-prepared soil pots, securing the seed afterward.

At this early stage, the cannabis seeds need regular watering, but be careful not to overwater. We recommend using a plant mister to ensure that the soil pots stay damp but not soaking wet.

Wet Paper Towel Method

The wet kitchen towel method is the most common method among home growers for growing cannabis because it holds moisture well and is readily available. Some home growers prefer absorbent paper, while some prefer cotton wool pads. However, they all follow similar procedures.

Prepare a flat surface and lay a sheet of damp paper towel on it. Place the weed seeds on it, making sure that they are a few centimeters apart. Once you are done with the arrangement, place another sheet of damp paper towel on top. 

Constantly ensure that both paper towels remain damp but not soaked. After some days, you should notice some white root tips shooting out. Once these root tips reach one to two centimeters in length, carefully transfer the seeds into individual soil pots prepared using the same guidance above.

Be very careful and gentle when transferring the seeds from the wet paper towels to the soil pots because they are very fragile. If available, we recommend using tweezers.

Planting Seeds Directly Into The Soil

If you are not careful and gentle enough and do not want to risk damaging your germinating cannabis seeds at their most fragile, you can plant the seeds directly into the soil. During seed germination, the first root tip is covered with some microscopic filaments that can be easily damaged if the seed transfer is not handled carefully.

More so, this method is safer because the two methods discussed above are proner to temperature fluctuations from their environment.

Fill the soil pots with high-quality soil and soak it with water. If available, add a root stimulator to the water. Poke a hole of about 10 to 15mm deep in each pot and place each seed into the hole.

Cover the hole loosely to secure the seed, and do not compress the soil above the buried seed. Constantly wet the spot where you place the seed to allow it to stay moist – don’t add too much water to soak the soil. We recommend using a spray bottle to add water to the soil. 

If you don’t want to soak your soil pre-planting, you can spray the holes to wet them before planting. Just ensure that there is adequate moisture around the seed because this encourages root development.

Place the soil pots in a damp area that is within the temperature range of 22 to 25°C (71 to 77°F). After four to ten days, you should see your seed germinating, with the roots going underneath the soil. 

If the soil pot is large enough to hold a mature cannabis plant, that is fine. Otherwise, you would need to move the entire plant and its soil to a larger soil pot, where you can apply other growing routines.

If you are on a low budget, the three germination methods discussed above are suitable for you. However, if you have some cash at your disposal, you can consider the following methods:  

Stone Wool Block Method

Weed seeds require 100% moisture and warm temperatures to germinate, but it is difficult to maintain the moisture content and ideal temperature range of 22 to 25°C (71 to 77°F) in the methods above. Even if you use a warming mat, it will only maintain a constant temperature and not the moisture content. 

Hence, you need to invest in stone wool blocks.

Stone wool blocks create perfect growing conditions for your cannabis seeds. Simply soak the stone wool block the same way you would soak a soil pot. The wool retains the moisture content and prevents the need for adding water during the seedling stages of germination. 

Stick the soaked stone wool blocks in a large plastic tub or bowl that has a lid and place it in a temperature-controlled cupboard. You have simply created a mini tropical climate for your seeds and do not need to touch them again until they are set for transfer to their final growing medium.

Under normal circumstances, your cannabis seeds should germinate in a day or two days when you use stone wool blocks. However, you may need to wait for the seedlings to be ready for transfer before moving them to their new medium.

Normally, the cannabis seedlings are ready for transfer once you see the root system shooting out downwards below the wool blocks, and this usually occurs about two or three weeks after germination.

Other methods involve using the Royal Queen Seeds (RQS) soil plugs and the Royal Queen Seeds (RQS) feminized starter kit.

The RQS soil plugs contain a well-crafted formula of ingredients specially made to help grow marijuana seedlings thrive. These plugs also provide the needed balance of aeration and water retention, ensuring that your marijuana seeds do not dry out.

Royal Queen Seeds (RQS) feminized starter kit, on the other hand, contains everything necessary to start your cannabis growing project.

Step 3: Add Sufficient Light

As soon as you transfer your germinating seed or young weed seedlings to their final soil pots or grow bags, you need to place the pots about 8 to 15 cm (3 to 6in.) away from sufficient light. This will help to promote plant growth and avoid stretchy seedlings. 

As the growing seeds require about 300 to 500 micromoles of light on their first day of sprouting, we recommend setting up a solar-powered fluorescent or LED light. This is not only cost-effective but will also reduce the stress of running electrical wires.

However, don’t forget to always clean the panels of solar lights to maximize their performance and lifespan.

Step 4: Monitor the Essentials

Add Water

Like every other living thing, your weed plants need water to grow. Water is the medium that transmits nutrients around the plant.

For indoor plants, you need to monitor the water in the soil regularly. Add some drops of pH-adjusted water each day the soil feels dry. 

For outdoor plants, tour cannabis may get all the water it needs from nature as long as there is regular rainfall. Otherwise, you would need to supplement water between rains.

Add More Nutrient

At the early stage, the seedlings need nothing more than a 24-hour light supply and water, except you did not grow them in wet, nutrient-rich soil. 

Depending on your chosen growing medium, you may need to add nutrients for the first two to three weeks. 

An easy way to know when to add more nutrients to the soil is by observing the leaves. Once the serrated leaves start to turn pale green, the nutrients are depleted, and your plant needs more nutrients.

If you do not add more nutrients in time, the leaves will eventually turn yellow, which is an indication that more nutrients are needed. However, once you add nutrients, the color of the leaves should return to green within a few hours or a whole day.

Note that nitrogen is the most needed nutrient for growing weed seedlings, especially during periods of high growth.

Allow Fresh Air 

Weed plants require fresh, moving air for strength and proper exchange of gasses. Outdoor plants are fine because they are exposed to gale and breeze. However, indoor plants need a fan for air movement, an exhaust to remove stale air, and windows for fresh air intake.

Your cannabis plant will have a stunted growth where there is a buildup of aspirated gasses.

Temperature 

The ideal temperature range for a cannabis plant is 22 to 25°C (71 to 77°F). Anything below or above this is extreme and can negatively affect the growth of the plant.

Indoor plants can easily achieve this optimum temperature with fans, cooling mats, grow light, and so on.

Pest Attack

Pest attacks are another thing you need to monitor. If you plant your weed indoors, know that a still environment can encourage pests and molds. Make sure that you properly balance the humidity around where you plant your weed for a healthy, pest-free environment.

If you plant your cannabis outdoors, slugs and snails are major pests against which to protect your plants. Slugs and snails can inflict significant damage on your weed seedlings and plants. However, we’ve got you covered. Here is a guide on how to get rid of slugs in your garden.

Generally, monitor your cannabis plants regularly and make sure that they are growing as expected. When monitoring your plants, look out for things like:

• Yellowing of leaves, 
• Spotting leaves, 
• Strange colorations, 
• Falling off of leaves, 
• Leaves curling up, 
• Smell,
• Rotting or dying of leaves.
• Stretching, and so on

Step 5: Sit Back And Watch

After about four weeks, your weed seedling is in its vegetative stage. So, you can sit back and watch your cannabis plant taking shape. Your cannabis plants can now metabolize on their own with light photosynthesis.

Necessary Steps To Follow When Growing Your First Marijuana Plant

Here is a summary of all the necessary steps you need to follow when growing your first weed plant:

• Choose healthy, high-quality cannabis seeds 
• Plant your cannabis seeds using the right medium
• Water the growing plants 
• Provide organic nutrients 
• Monitor the essentials – light, temperature, air, pests, and so on.

How to Germinate Cannabis Seeds – Conclusion 

Weeds are easy to grow, and we believe that our guide above will help you grow your first weed plant successfully. All you have to do is choose any of the methods above that are best suitable for you.

All the germination methods explained above have varying degrees of success. So, it is important to know that even with advanced growing experience and top-notch kits, you may still end up with a low growth rate or a few failed seeds. 

Frequently Asked Questions (FAQs)