What is the best way to germinate cannabis seeds?

A seed sprouting a root on a wet surface

This article explains how to correctly germinate your cannabis seeds, covering everything from optimum temperatures, to potting your seedlings and transferring them outdoors (or inside under lights).

The best way to germinate cannabis seeds requires only two saucers or plates and some moist tissue. Here is a step by step guide.

Warning!
Unfortunately, regulation and implementation in respect of cannabis seeds often differ from country to country. For this reason we advise you as a matter of urgency to make inquiries about the regulations to which you are subject. Read the complete disclaimer here.

Step 1. The setup – How to germinate cannabis seeds

Line the bottom of the first plate with a few layers of wet tissue and drain any excess water from the plate.

Seeds should be placed on top of the tissue, allowing each seed as much space as possible.

Place another few layers of moist tissue on top of the seeds, again allowing excess water to drain off.

Lastly, cover everything with the second plate, upside down, to form a ‘clam-shell’ shape – this will create the dark, moist environment necessary for germination.

Germinating cannabis seeds using plates

Step 2. Germination – How to germinate cannabis seeds

Place the plates somewhere warm (21ºC) and away from direct light.

Check the seeds every day to ensure that the tissue does not dry out. Spray the tissues with water if necessary.

Within a few days some or all of the seeds should open and put out a root. It is common for cannabis seeds to open within 72 hours of being put in the germination medium. Less commonly, some seeds may need up to 10 days or even two weeks to open and put out a root.

When the first few millimetres of root have emerged from a germinated seed, each one should then be carefully transferred to a small container of growing medium (soil, coco-fibre or rockwool).

Germinating cannabis seeds using plates

Step 3. Potting – How to germinate cannabis seeds

Make a hole in the growing medium that is about twice as deep as the seed is long, so that each germinated cannabis seed sits 2-5mm below the surface.

Place the cannabis seed, root first, into the hole and cover with a small amount of growing medium – just enough to block light, not enough to obstruct the seedling when it emerges.

Cannabis seedlings usually emerge from the growing medium 24 to 72 hours after the germinated seeds are planted.

New seedlings planted in soil

Step 4. The seedling stage – How to germinate cannabis seeds 

New seedlings should be given access to bright light from the time they emerge. Care should be exercised in the first week or two, as seedlings are still quite delicate.

Seedlings intended for outdoors should be acclimatised to direct sunlight by placing them on a windowsill inside the house and increasing their exposure to direct sunlight by an hour or two per day.

Seedlings intended for indoors may emerge into an artificially lit environment with no problems. If using HID lighting, seedlings should be kept a minimum distance of 50 to 80cm from the bulb. If using fluorescent light, seedlings can be kept a normal distance from the tube/bulb.

A tall plant outside in the sun versus a smaller plant inside

  • Disclaimer:
    Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.

Comments

17 thoughts on “What is the best way to germinate cannabis seeds?”

  1. I lightly score my seeds by shaking them inside a rolled up piece of sandpaper – sandpaper side on the inside before leaving them in a cup of water for a few hours to hydrate. I then place them between wet (good quality) paper towel per instructions above. I find using an old plastic takeaway container with a heatmat below keeps the humidity high and with good end results.

  2. I have found out that the best and fastest way is to take a glass of clean/filtered water and place the seed right on top of the water (floating – NOT immersed in it!). If the seed is viable it will sprout in no more than 48 hours. Right after that you plant it in your pot/soil etc and you’re done.

  3. Tammy Bowman

    Take aluminum foil flatten it out and put on top of your dirt it detects planes and grow it just like a tomato plant

    1. Detects planes? Like magnetic? I’ve always has best success 24-48 hours soaked In water, spring water if possible. Usually do this in a shot glass, once they pop I’ll take a paper towel fold so it’s 2 layers then fold once more so you know where center is. Dump the seed in the middle of the edge and the true center (reason we folded a 2nd time)as well as the water just enough to saturate the paper towel. Do not soak! Carefully with the seed in the middle using sterile tweezers turn so the tap is growing down. This will prevent circling and tangling if doing multiple seeds. Now you can fold the other half so your seed will be “sandwiched” between 2 layers. At this time carefully take a corner and the waters attraction should keep your paper towel from unfolding but just in case be gentle. Holding it from 1 corner you can dangle it over a cub or the original shot glass so any extra water runs off. Now take a standard zip or press n seal sandwhich bag and slide your napkin in Carefully . REMEMBER which way was down! Work the air out making jt flat snd seal. Find a temperate dark area around 70°. A cabinet works we’ll as your going to prop it up with taproot facing downwards. Now just close it up and wait in 24-72 hours checking once a day. In rare cases you could have a 1/2″ tap root in the first 24 hrs some may take 4-5 days. Once the tap is about 1/2″-3/4″ long its ready for transplant into its first small pot. With this paper towel method I typically have 100% success.

  4. Hi guys

    Can you leave your seed to develop longer roots in the germination phase and can this make them better to grow or is a big no no?
    Last year, I had 2 seeds that had really long roots with lots of secondary roots coming out when they were planted, one of which died after a couple of weeks and the other grew into a huge plant.
    The other two seeds only had a short germinated growth and both died almost immediately after planting so not sure what I can learn from this…lol

    Appreciate any thoughts and advice

    Thx Christina

    1. Mark - Sensi Seeds

      Hey Christina,

      Unfortunately, legal restrictions mean we can’t answer grow-related questions or give grow advice on this blog. However, other readers of this blog will often answer questions like yours.

      Please check out the following articles on our blog which I think you may find of use, and I hope you continue to enjoy the blog!

      What are the best conditions for seedlings

      When can seedlings be put under lights or in the sun

      The Life cycle of Cannabis: from seed to harvest

      With best wishes,

      Mark

  5. How often do you water and how wet should the plant be? Please.
    Also if they are outdoor plants do you need to keep them covered with clingfilm for a wee while or do you just hope for the best. Thanks

      1. Just drop the seeds in water, they will sprout , don’t have to use a towel and check it all the time , drop it in the water , let it float then it will sink and the root will grow out ,let the root get 1/4 inch and plant it where it’s going to grow , 8 hours sunlight starting as soon as it is out of the soil. Always grows great , don’t have to transplant from cup to gallon to bigger and bigger , if it’s growing outside put it where it stays , always does just fine.

  6. marijuanatravels

    I recommend this article to all breeders and cultivators who plans to germinate seeds and to some who don’t know how to germinate seeds, this article has the best and perfect ways on how to do it.

  7. I have large bay windows at my condo which get about 11-12 hours of light per day. They are tinted but warm. I grow other indoor plants there perfectly. Is an ok place for my pot plants?

    1. Scarlet Palmer - Sensi Seeds

      Hi Ken,

      This sounds like a great place for all kinds of plants! I recommend you have a look at autoflowering varieties, as otherwise light pollution may negatively affect the flowering cycle. Good luck, and happy gardening!

      With best wishes,

      Scarlet

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    The Sensi Seeds Editorial team has been built throughout our more than 30 years of existence. Our writers and editors include botanists, medical and legal experts as well as renown activists the world over including Lester Grinspoon, Micha Knodt, Robert Connell Clarke, Maurice Veldman, Sebastian Maríncolo, James Burton and Seshata.
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