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Hopefully all of you aspiring growers have been able to get your seeds so we can move to the next step: germination.
Take great care handling seed and seedling. Most flower and vegetable seeds are simply planted directly in the soil, but because of the value of cannabis seeds, germinating seeds prior to planting is encouraged. Growers can achieve a much higher survival rate by germinating in a non-soil medium and then transferring the seed to soil once the tap root has emerged from the seed.
Here is one of the simplest and most successful methods: Put a double layer of paper towels on a dinner plate, then thoroughly soak the towels with water and tilt the plate to drain off the excess. Place your seeds on top of the wet towels and cover with another double layer of soaked paper towels. Be sure excess water is drained off—you don’t want the seeds to be swimming.
Cover the plate with an upside-down plate or pot lid. A plastic bag or plastic wrap also works. Don’t make the seal tight—you want to leave some openings to allow air flow.
Keep the germinating seeds away from direct light. For best results, keep them at about 75 degrees Fahrenheit. A radiant heat source, like a heating pad, helps expedite the process. If you’re using a heating pad, be sure to keep the heat setting on low and place a folded hand towel between the heating pad and plate: Direct contact between the plate and heat source can cook your seeds.
Under the right conditions, seeds usually open in one to five days, so check them daily. Do not allow the towels to dry, and add water as needed to maintain moisture. Some seeds can take as long as 10 days to germinate, but if seeds have not opened within 10 days, they are not viable.
When the seeds open, the first thing to emerge is the root. Once the root sprouts it can grow quite fast.
When the root grows to a few millimeters in length, the seed is ready to be transferred to soil. Always take great care not to damage the tap root when handling. The best soil to use for a sprouting baby ganja plant is a “seed starter” or “seedling” mix. These are light neutral blends with very little fertilizer. Heavily fertilized soils will kill seedlings quickly, and cannabis seedlings prefer loose, aerated soil that their roots can easily penetrate. A bag of good starter soil is easily identifiable: When you pick it up, it should feel light and fluffy. Soils that are heavy and compact are not good for seedlings.
Now, on to potting (no pun intended). A healthy seedling will be ready for transplanting into larger container, with richer soil, in about a month. A 16- to 20-ounce container is ideal for a seedling’s first home (many growers use a Solo cup). The container must drain, so punch some holes if needed.
Fill your container with pre-moistened soil and create a hole about a half-inch deep for your seed. The tip of a pencil works well for making the right sized hole. The seed should be about a quarter-inch below the surface.
Place your germinated seed, root down, into the hole and cover lightly. Do not pack the soil on top of the seed; a light protective layer of soil is all that is needed.
Once they sprout in one to three days, new seedlings will need lots of light, and fluorescent grow light works best. Give your baby ganja plants 16 hours of light per day.
It’s very important to have a breeze on your plants immediately. A fan placed at the proper distance and speed should create a breeze just strong enough so your plant “dances,” but not so strong that it’s bent in one direction.
Without a breeze, indoor ganja plants won’t receive the stimulus needed to develop sturdy stems and branches, which the plant will need to bear the weight of big, sugary buds.
The Potanist is written by Bud Baker and Herb Green (yes, those are pseudonyms; yes, they are real people). Reach them at [email protected]
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How to Germinate Cannabis Seeds
Germination is the beginning of your cannabis seeds’ life and is easy to master. At this crucial stage, seeds grow and sprout into young seedlings. The best genetics deserve the best start, and all you need is two plates, some paper towel, and water. Apply the best germination method today and enjoy a great harvest.
1. Germination set-up
Prepare the first plate by lining the inside surface with two to three layers of damp paper towel. Drain excess water from your plate.
Place cannabis seeds on the top surface of the damp paper towel. Approximately three per plate; ensure they are not touching but are evenly spaced apart.
Add only a few layers of damp paper towel on top of the seeds, and let any excess water drain from the plate. Too much water lowers the chance of successful germination.
To complete the set-up, place the remaining plate upside-down and on top of the first plate, resembling pearls inside a clam.
Cannabis seeds need a dark, warm, and humid atmosphere to germinate.
Around 21°C (70°F) is perfect. Check the paper towels every second day and if required, spray with water to keep conditions moist for your seeds.
After a few days, tiny roots will begin to emerge. Congratulations! Your seeds have survived their first stage of life. Don’t worry if some of your seeds have not yet changed, they may just need a little more time as germination can take up to 14 days.
3. Plant of the seeling
Once the roots are a few millimetres long, they are ready to be delicately transferred to a small container filled with your growing medium of choice (rockwool, coco-fibre, or soil).
Make a hole in the growing medium that is 2 – 5 mm deep. Use tweezers or your fingers to transfer germinated seeds gently into the hole (root pointing down) and lightly cover with a fine layer of your medium. Do not pat it down too hard. The stem and the first tiny set of leaves, called cotyledons or ‘seed leaves’, should begin to emerge 24 to 72 hours after the seeds are planted.
4. Supplying a light source
Seedlings must be exposed to sunlight once they sprout. Ensure this is a gradual process as too much heat causes stress and will stunt growth.
Find a sunny place where you can begin to increase sun exposure, such as a windowsill. Ensure sun exposure is increased by an hour or so a day.
For an indoor plant you can use a fluorescent light (keep normal distance from bulb) or HID lighting (50-80 cm from the bulb).
Take care in the first week or two, as seedlings are still quite delicate and sensitive to the elements. They won’t need a lot of attention until the vegetative stage so avoid overhandling.
Germination is the beginning stage of the growing cycle, and this easy-to-follow guide gives your premium genetic cannabis seeds the best start to life. Whether you are a first-time home grower or a well-seasoned gardener, share your experience or any questions in the comments down below, as well as your tips and tricks!
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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.
22 thoughts on “How to Germinate Cannabis Seeds”
Hi, Once seeds have sprouted, how long can or should you leave them to grow under 24 hr lights before moving to your outdoor garden?
Good afternoon Ken,
I hope you’re having a great day.
For the vegetation process, a light schedule of 18 hours of light, and 6 hours of darkness is preferred. Many growers get plants acclimatized to outside by placing them in a window, or under direct sunlight for a few hours a day.
Thanks again, and have a great day!
Hello everyone, all these suggestions are wonderful but I think a lot of you make it sound a little overwhelmingly. I’ve been very successfully cultivating for decades and I’ve always just placed my seeds, be it 1 or 100, in between 2 folded sheets of tissue which I’ve made wet with tap water. I then place them on a tray or plate in a warm dark area , such as an airing cupboard and leave for how ever long they take usually, 12 to 24 hours. The ONLY thing I do which takes effort is PH balance the water I germinate them in and I’ve only lost 5 seeds in nearly 40 years .
Good afternoon Paul,
I hope you’re having a good day,
Thanks for sharing your experiences with germination. pH balancing is a great tip You also might be interested in our new Jamaican Pearl Feminized Grow Report
Thanks again, and I hope you continue to enjoy the blog,
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.
Good morning Jonny,
Thanks for sharing your methods for germination with us, the heat mat and low-humidity are great tips!
Thanks again, and I hope you continue to enjoy the blog,
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.
Good morning Mary Jane,
Thanks for your support, and for sharing your experiences with germination!
You might also be interested in our article on The Life cycle of Cannabis: From seed to harvest.
Have a great day!
What happend if they sink I had em sink they came out fine
Are you saying they sprout in the glass of water and don’t “drown”?
Take aluminum foil flatten it out and put on top of your dirt it detects planes and grow it just like a tomato plant
Good morning Tammy,
Thanks for getting in touch with Sensi Seeds, and sharing your germination method with us!
Thanks again, and I hope you continue to enjoy the blog.
With best wishes,
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.
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
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!
With best wishes,
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
This article, about how to water cannabis plants, should answer your questions. I can’t help you with the clingfilm one though, as it depends on the climate. Good luck, and happy gardening!
With best wishes,
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.
Good afternoon Graham,
Thank you so much for sharing your experiences with germination.
Thanks again for your comment, and I hope you continue to enjoy the blog.
Have a great day!
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.
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?
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,
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How to Plant Cannabis Seeds Indoors
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Growing cannabis at home can be a fun project and a nice way to have your own cannabis plants on hand. You may want to grow cannabis indoors due to inclement weather in your area or due to a lack of green space in your yard. Start by germinating the seeds. Then, plant the seeds in soil or in a starter cube. Once the seeds have been planted, care for them properly so they grow and thrive.
- After 12 hours, place the viable seeds on a towel.
Wet one paper towel and put it on a plate. Paper towels are thick enough to retain the moisture needed to help the seeds germinate. Place one paper towel under running water until it is wet to the touch, but not dripping wet. Use a ceramic dish or plate, as it will be strong enough to hold the towels and the seeds. The paper towel should cover the dish or plate.  X Research source
- If you do not have enough space on one plate for all your seeds, soak two more paper towels and put the remainder on a new plate covered in a wet paper towel.
Wet other paper towel and place it over the seeds. Make sure the wet towel makes contact with the seeds.  X Research source
- You can try using a heat lamp near the seeds to keep them warm. Do not warm the seeds up too much, as you do not want your heat source to dry out the paper towels.
- If the seeds become too dry, they could die and never germinate.
- Be very careful with the seeds as they open. Avoid prodding, pulling, or touching the seeds, as you do not want to damage the roots.
- Any seeds that have not opened and grown roots within a few days should be discarded, as they are not viable.
- As an alternative to soil, you can use starter cubes from your local nursery or online. Starter cubes are pre-cut growing pods made of composted bark. They contain a hole where you can place the cannabis seeds and grow them in good conditions. Basic starter cubes are inexpensive and easy to use.  X Research source
- If you make planting holes that are too shallow, the seed’s roots will not have enough soil to grow well. If you make the planting holes too deep, the seed will have a difficult time sprouting.
- Do not pull or tug at the seeds when you pick them up with tweezers. If they are stuck to the paper towel, wet the towel with water to make the seeds easier to pick up.
- Do not press hard on the seeds when you cover them, as this can disturb their growth.
- If you are using starter cubes, pinch the top of the holes in the cubes closed.
- Maintain a growing temperature of 75 to 85 °F (24 to 29 °C) for the plants so they thrive.
- Stick to a regular watering schedule so the plants get enough moisture. You can plan to spray the plants in the morning and then again at night so they get the water they need.
- Grow lights range from $200 to $1,200 USD depending on the size and model.
- You can get cool white grow lights at your local hardware store or online.
Avoid touching or handling the seeds as they grow. Touching or handling the seeds can damage them and stunt their growth. With the right growing conditions and care, your seeds should sprout and poke out of the soil within five to ten days.  X Research source
More than 12 hours of light a day for about 4-6 weeks as the plant matures will be enough. Once the plant is a decent size, you may induce flowering. Switch the plant to a timer of EXACTLY 12 hours of strong light (the more sunlight the plant gets, the more energy it can devote to flowering).
Yes, it is bad for the plant to have water constantly sitting at the bottom of the pot. It could make the roots rot over time.
You can actually find LED lamps made for growing plants online. If you don’t want to bother with that, you can just get a purple light to grow them under. There are many articles online talking about the effects of colored lights on plants.
If you plan on growing short, fat plants, they should be at least 6′ apart. You don’t want the plants rubbing on each other or shading the other plants. You will also want to select a spot to ensure all plants will receive maximum sunlight.
You can start as soon as you see two little leaves budding. During that time, make sure to use distilled water when watering them.
Cannabis thrives in a comfortable room temperature when grown indoors, or a little warmer – not too dry, not too humid. If it feels too hot or too cold for you, it’s probably too hot or too cold for your cannabis plants.
You can’t. You can try keeping it by a window, but you still won’t have much success. Lights aren’t that expensive, look on Amazon.
Yes, rain water is fine for any plant. The use of distilled water is to keep from adding tap water contaminants.
Keeping the plant from “stretching” is simple. Place the lights closer to the top of the plants. There are good video examples on YouTube showing two seeds started at the same time and placed under lights at different heights. The plant with inadequate lighting actually “reaches” for the light, growing tall and thin with longer internodal gaps. The seedling with closer light grows short and squat, with less stem between leaves (internodal distance), which means a better frame and plant structure for supporting the massive buds that you want to grow. As the plant grows, raise the lights with it. (Most folks suggest somewhere in the 16-30 inch range from source to canopy.)
The cultivation of cannabis is considered illegal in many jurisdictions. Make sure it is legal to grow cannabis in your area.
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About This Article
This article was co-authored by wikiHow Staff. Our trained team of editors and researchers validate articles for accuracy and comprehensiveness. wikiHow’s Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards. This article has been viewed 1,330,133 times.
To plant cannabis seeds indoors, first soak the seeds in lukewarm tap water for 12 hours. Discard any seeds that float to the top. Then, place the seeds on a damp paper towel on a plate with 1 inch (2.5 cm) of space between each seed. Cover the seeds with another damp paper towel. Keep the seeds in a spot that remains between 70-80°F (21-27°C), and spray the paper towels with water whenever they start to dry out. The seeds will sprout in 2-3 days. When they do, fill pots or a growing tray 3/4 of the way with loose potting soil that has a pH between 5.8 and 6.3. Press the soil down lightly, leaving some air in it. Then, use a pencil to poke 1 inch (2.5 cm) holes in the soil. Place the sprouted seeds vertically in the holes and fill the holes with potting soil. Water the soil thoroughly and place the pots or tray in a spot that’s always 75°F (24°C) or warmer. Set up a grow light over the seeds and leave it on at all times. Water the seeds every day so the soil doesn’t dry out. The seedlings will emerge in 2-4 weeks. To learn how to use cool white grow lights to help your cannabis seeds grow, keep reading!
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