How to germinate marijuana seeds

Learning how to germinate marijuana seeds successfully is the first hurdle to overcome to get those huge yields you so badly want. Germinating marijuana seeds it isn’t as simple as just putting a seed in soil and watering it. To give you the best possible chance of success there are a few methods that you can use to tip the odds in your favour.

What is a good germination rate?

Different germination methods have different levels of success. Even with top shelf genetics you will occasionally get duds, with mother nature unfortunately that sometimes just happens. However on average you should be able to get 80% + germination success when you are using the right techniques and good quality genetics.

How can I tell if my seeds are good quality?

Cannabis seeds like all seeds vary in shape, colour and appearance, however there are a few tell-tale signs that show your seeds are of good stock. Cannabis seeds develop part of their colour and appearance as the plant matures, if the seeds are harvested too early it is visible through their colour. Seeds that have a dark colour are normally good and have been harvested at the right time, especially if they have tiger stripe like pattern on their outer shell. Whereas seeds that are pale or white in colour are often premature and less likely to germinate.

How to store cannabis seeds

Before we talk you through how to germinate marijuana seeds, it is important that you understand how to store them correctly first. If you are storing them for short periods then in a dark cupboard or drawer should be fine, but ideally, they should be store inside a refrigerator and kept at around 7°C.

  • Keep them in airtight zip lock bags
  • Keep the bags inside an airtight Tupperware box (this protects them against fridge moisture)
  • Wrap them in something dark
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7 steps to successful marijuana germination

In the wild cannabis plants play a game of numbers and often produce up to 2000 seeds at a time, with a high chance that many of them will fail to germinate or be eaten before they get a chance to grow. However, rather than leaving it up to chance it is relatively easy to replicate the ideal conditions that your seeds need to flourish. Just follow these seven keys to successful marijuana germination.

Moisture: Seeds and Seedlings love moisture and must be always kept moist. Purchase a spray bottle or mister to water them gently.

Humidity: Seedlings like to be humid, so try to keep the growing environment at around 60-90% relative humidity for ideal germination conditions. 

Warmth: Keep the temperature nice and warm and make sure any water that is used is also warm. Germination does happen in cold weather, but warmth will increase the likelihood of success. Ideal germination temperatures – 22°C and 25°C (71–77°F). Use a gentle light such as a T5 to germinate them under.

Be gentle: Seeds are very delicate, be gentle with them especially after the taproot has emerged. You should avoid touching the white taproot. Some growers use tweezers to transplant their newly germinated marijuana seeds to soil.

Plant root facing down: When you plant the seeds into their growing medium always make sure the root is facing downwards. This will give the seedling the best possible chance of breaking through the surface of the soil and surviving. Read below for a step-by-step guide on how to plant marijuana seeds once germinated.

Plant ¼ to ½ an inch deep: When you plant your seedlings don’t plant them too deep. A seed only has so much energy to break the surface of the soil, if planted too deep the seedling will never emerge. You should plant your seeds around ¼ to ½ an inch deep to give them the best chance of success.

No nutrients: This is an area where many newbies make mistakes. Seedlings are delicate and nutrients can kill them if they are administered too early. Do not give your seedlings any nutrients until at least the 3rd set of true leaves. I personally leave it a little later than this to make sure they are strong and stable first.

Germinating marijuana seeds

How long do marijuana seeds take to show their taproot?

Using correct marijuana germination methods, seeds should begin to show a tap root within 12 – 48 hours of becoming moist. However, this depends on how thick the shell is and how much water has penetrated the shell.

Before the tap root of a marijuana seed appears, three environmental principles should be present; Warmth, moisture and darkness. Once the taproot is visible and the seed is planted, you will usually see the first set of leaves breaking the surface of the soil within 24-48 hours.

What are the best methods to germinate marijuana seeds?

How to germinate marijuana seeds using Rapid Rooters (highly recommended)

Rapid rooters are very easy to use and offer excellent germination rates because they are specifically designed for seeds. Each plug has a small hole in the top for inserting a seed. They are made of natural water absorbent materials such as dried tree bark that are similar in texture to a firm soil.

The great thing about Rapid Rooters is that you do not need to take the seeds out to transplant them, which minimises the risk of damaging the delicate tap roots. Rapid Rooters are also highly versatile and can be used to transplant into soil, hydro or other soilless mixes with ease.

You can get rapid rooters and starter trays from amazon for as little as $12 for 50 plugs.

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TIP – Counteract your failure rate? If you are growing lots of seeds in one go, you can insert more than one seed into each Rapid Rooter plug. This increases the chances of germination. Alternatively, I prefer to use around 10% extra seeds and Rapid Rooter plugs that I actually need but just stick to 1 seed per plug to account for any seeds lost from non germination.

Step-by-Step with Rapid Rooters

What you will need: Rapid rooter plugs and a nursery tray and a source of white light such as T5’s.

Most rapid rooters come with a nursery tray, if yours does not I would advise purchasing one because it makes germination much easier and allows you to keep things tidy with less spills. Alternatively if you only want to germinate a few marijuana seeds you can use a humidity dome or Tupperware box – as long as it is a seal environment that encourages humidity.

  1. First off start by soaking your Rapid Rooter plus in distilled water for 12-24 hours. If you do not have distilled water, you can boil some and then let it cool then use this.
  2. Squeeze out any excess water so that they are left damp.
  3. Use a pen or some tweezers to loosen the hole before placing one seed into each hole of the Rapid Rooters.
  4. Tear a small piece off of the bottom of the rapid rooter and use to plug the hole after you have put the seed inside. Seeds like darkness so this will help to block out any light.
  5. Place the Rapid Rooters into their nursery tray or humidity dome.
  6. Place them under a white grow light such as a T5. This step is not essential but highly recommended. I have found that it keeps them warm and increases humidity creating the ideal environment to germinate marijuana seeds. If you are not doing this, make sure you keep them somewhere warm or use a heat mat.
  7. Moisten the Rapid Rooters a few times each day with distilled water and use a misting spray to keep the environment humid.
  8. Once the roots are showing through the bottom of the Rapid Rooters then you can transplant them into their growing medium. 

How to germinate marijuana seeds in Rockwool Cubes (best for hydroponics)

Rockwool cubes are similar in concept to Rapid Rooters but personally they are not quite as versatile or successful. However they are more the best method to germinate marijuana seeds for hydroponics growing.

Step-by-Step to germinate in Rockwool Cubes

What you will need: Rockwool Cubes, pH’d water, humidity dome or similar and a gentle grow light such as a T5.

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  1. Start by soaking your Rockwool Cubes in water that has been pH altered. The pH in Rockwool Cubes is usually too high for cannabis seeds.
  2. Squeeze out any excess water so that the cubes are damp but not wet.
  3. Push the marijuana seed into the hole. I normally use a toothpick to push it in a bit deeper. You want to push it in around ¼ to ½ an inch.
  4. Placed the Rockwool into its humidity dome and under the light.
  5. Once you see the roots coming through the sides or bottom and the seedling coming up they are ready to be transplanted.

You can get a pack of rockwool cubes for as little as $8 – $10.

TIP – Test your pH: pH can be too high in Rockwool cubes. Use a pH meter to test the runoff pH before using them to germinate with. If it is too high, then rinse them well with pH adjusted water and test again.

How to germinate marijuana seeds using jiffy pellets

Jiffy Pellets are like Rockwool Cubes, but they are an organic mix which is made up of peat moss. Jiffy Pellets are small dried compressed discs with a net covering, that once soaked will expand. 

They are most commonly used with Soil and Coco Coir but are not suitable to use with hydroponic grows.

Step-by-Step with Jiffy Pellets

What you will need: Jiffy Pellets, pH’d water, humidity dome or similar and a gentle grow light such as a T5.

  1. Soak the Jiffy Pellets in water for 10-15 minutes.
  2. Once the pellets are puffed up and have absorbed water put them in their tray and use a pencil to poke a hole about ½ an inch deep into each pellet. This will make it easier to plant the seed.
  3. Push 1 seed into each pellet and pinch around it to cover up the seed. It is important to do this so they are in the dark.
  4. Place the pellets in their tray under a light or on top of a heat mat.
  5. Make sure the pellets stay warm and moisten them a few times a day with a gentle spray of water.
  6. You should see within a few days the seedling breaking up through the surface. They are now ready to transplant.
  7. Transplant them into your desired growing medium.

You can get a pack of Jiffy Pellets for as little as $6 – $10

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TIP – Strengthen your seedlings: If your stem grows too long before you have transplanted your seedling, this can make the plant weak and prone to damage. To counteract this when you transplant the seedling to soil, bury a portion of the stem under soil this will help to stabilise the seedling and prevent damage. As long as all of the leaves have access to light the plant will still grow.

How to germinate marijuana seeds in a glass of water

This is probably the most popular method to germinate marijuana seeds because of its simplicity. This method is also very effective with seeds that have harder shells because they are completely submerged and subsequently take in more water.

What you will need: A glass, paper towels and two plates.

Step-by-step glass of water method

  1. Fill a glass halfway with lukewarm water (ideal water temp 22°C (71°F).
  2. Put the glass somewhere reasonably warm in your house so the temperature of the water does not get too cold. You should see that most viable seeds will sink within a few hours.
  3. Leave them in the water for up to 12-24 hours, you should start to see after 24 hours that some of the shells will have started to split.
  4. If the seeds have a clear tap root poking out of the shell, then you can plant them at this point.
  5. If your seeds still have not got a clear visible tap root do not worry, you should then put them on a plate sandwiched between a few layers of paper towels.
  6. Wet the paper towels around them with warm water – use enough water so it soaks all the way through the towels.
  7. Put another plate on top so that they are cocooned in between two plates and leave them somewhere warm for another 24 hours.
  8. Periodically remoisten the paper towels every few hours with warm water so that they don’t dry out.
  9. Check them after 12-24 hours and see if they have a tap root, if they don’t put them back. 
  10. After 24-48 hours between the paper towels even the toughest of cannabis seeds should have started to show a root and should be ready to plant.
  11. Once you have successfully germinated your marijuana seeds carefully plant them with the root facing down in soil 1/4 – 1/2 an inch deep.
Germinating cannabis seeds in glass of water
Cannabis seeds germinated in water

How to germinate marijuana seeds with paper towels

This method is very similar to the glass of water method but instead of submerging the seeds overnight in water you put them straight in between paper towels. This method is my preferred way and is one of the most easy ways to germinate marijuana seeds successfully.

Step-by-step paper towel method

What you will need: paper towels and two plates or a Tupperware box.

  1. Line a plate with some paper towels.
  2. Place the seeds on the paper towels with about 1cm of space between each seed to give the roots enough room.
  3. Sprinkle on some warm water or if you have a mister spray them so that the seeds and towels are damp.
  4. Layer another paper towel on top of the seeds and damped this with warm water. 
  5. Now put a plate on top so that the seeds are cocooned between them.
  6. Put the plate somewhere warm or put a germination heat mat underneath them.
  7. Remoisten the paper towels every 3-6 hours or whenever they begin to dry out.
  8. After 24 hours carefully check the seeds. You are looking for a tap root of at least 3-4mm – Once you see this, they are ready to be planted.
  9. If they require more time put the seeds back under again and repeat this. It can take up to 72 hours for some seeds.
  10. Once they are ready to be planted be very careful with them because the taproots are incredibly delicate. Prepare the soil in the pots and make a hole about ¼ of an inch deep with your finger.
  11. Carefully transplant the seeds, some people use tweezers here so as not to damage the tap roots. Place one seed in the hole with the tap root facing downwards. This is very important to do if you want your plant to grow.
  12. Gently cover the seed with soil and spray the soil with water 1-2 times each day.
Germinating cannabis seeds in wet paper towel
Cannabis seeds germinated in wet paper towel

How to germinate marijuana seeds direct in soil

Possibly the most straight forward method is to germinate marijuana seeds directly into soil. It is one of the most common methods among old school experienced growers. It is easy to germinate seeds using the direct to soil method, however germination rates are normally slightly lower. The benefit to growing direct into soil is that you do not need to transplant the seeds, which means there is less chance of damaging the taproots.

Step-by-Step direct to soil method

What you will need: Soil suitable for growing, a pot, pH’d water, humidity dome or similar and a gentle grow light such as a T5.

  1. You should ideally use soil that has a pH of around 7.0.
  2. Make a hole in the surface of the soil with a pen or your fingertip about ½ an inch deep.
  3. Place the seed into the hole and lightly bury it so that it can still easily break the surface.
  4. Make sure that soil is moist and keep it moist with a spray a few times each day.
  5. To keep them warm place them under a light T5 grow light or something similar.
  6. Within a few days you should see that the plant has begin to break the surface of the soil.

TIP – Create a microclimate: To create a humid environment on a budget, cut a 1ltr coke bottle in half. Turn the bottom half upside down and place it over your seedling. This will create a makeshift humidity dome that can be used while your plants are young.

A marijuana seed being germinated in soil
Germinating a cannabis seed in soil

How to plant marijuana seeds once germinated

Once you see that you have successfully germinated your marijuana seeds, and the taproot is a few millimetres long, you should plant the seed. Taproots are very delicate and can easily break or be contaminated, so be gentle and sterilise anything you use to touch them.

For beginners I would always recommend using Rapid Rooters, this is the easiest method because they are versatile and can be planted into any growing medium. Because the seed germinates into the Rapid Rooter you do not need to take out the seed, you can just place the Rooter plug directly into your soil. This reduces the risk of damaging the taproot.

If you are using the glass of water method or paper towel method which I know plenty of old school growers will be using, then that is fine but follow these steps.

Planting your germinated marijuana seeds in soil

  1. Once the taproots are a few millimetres long they are ready to be planted.
  2. Make a hole in the soil with your finger or the end of a pen that is about ½ an inch deep. Ideally wear gloves or sterilise your hands first to prevent contaminants touching the seedlings.
  3. Plant the seedling in the hole root facing down and lightly bury some soil over the top so that it is covered but can easily break the surface.
  4. Lightly water the soil with a spray or misting bottle, keep the soil damp but never wet.
  5. Place them under a gentle grow light such as a T5, this will help to keep them warm.
  6. Water them with the spray a few times each day to keep the soil moist.
  7. After a few days you should see the seedling break the surface of the soil.
  8. DO NOT add any nutrients until the plant has shown its 3rd set of leaves.
Hand making a hole to plant germinated cannabis seeds
½ an inch deep is about the right depth to plant the germinated seeds

Congratulations, you have just learnt how to germinate marijuana seeds. The first hurdle to overcome to achieve big yields. Have a read of our other articles to help you on the next stage of your grow.

Joe Musgrave

An avid 420 enthusiast, grower, smoker and writer. Joe writes non stop, sharing his extensive knowledge in the field of cannabis with the wider online 420 community through blogs like ours at High Yield Strains.

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