To start your cannabis grow, you will most likely be starting from seed. In this guide on how to germinate cannabis seeds, you will learn how to germinate your seeds with a 95% success rate.
Cannabis seeds will germinate very quickly, and as long as you have bought seeds with good genetics, from a well respected seed bank, your seed should be popped, and growing above ground within a week.
Germination is Quick!
If kept under the right conditions, a cannabis seed will germinate, grow root, and shoot above the medium within 5-7 days!
You may be eager to get started, but take your time, and let nature take its course. The cannabis seeds will need a stable environment when they are germinating.
Be patient, as long as you have followed this guide, your seed should germinate within a week.
If you need any more help with germinating your cannabis seeds, feel free to ask for help in our cannabis growers forum
Contents
- What you Need to Germinate Cannabis Seeds
- Root Stimulators
- Propagator
- Humidity Domes
- Lighting
- Nutrients
- Germinating Your Cannabis Seeds
- First Growth of a Cannabis Plant
- The Shoot
- Lighting and Light Cycle
- Temperatures and Humidity
- Feeding Schedule
- Repotting and Transplanting
- Moving into Veg
What You Need to Germinate Cannabis Seeds
Cannabis has grown for thousands of years, without the help of anyone germinating seeds! It is nature, and all you really need to germinate a cannabis seed is four things:
Water
Warmth
Air
Time
As long as the seed is kept in the optimal environment, it will germinate. To offer your seeds the best start in life, there are things you can use to make sure the environment is optimal for germination.
Root Stimulators
When a cannabis seed is first germinated, a small white root will push its way out of the seeds casing. When this root touches the medium, it will benefit from having some beneficial bacteria to help it grow.
Bacteria is important to the roots of a cannabis plant. Having a good supply, of good bacteria, will help the roots grow more, and the plants eat more.
Use some Great White, or Eco Thrive to help your seed get the best start. These are not vital, your seed will germinate anyway, but using some root stimulators will get the roots growing quickly, and they will also grow stronger.
Propagator
You will need somewhere to keep your seed, whilst it grows its roots and shoot. Seedlings like high humidity, and a constant warm temperature. For best results, a heated propagator can be used.
If you do not have a heated propagator, you will need something that is on for 24 hours, that will produce a small amount of heat.
Where to Keep Germinating Seeds
Use a heated propagator, but if you don’t have one, use a device that is on for 24 hours a day, and place your seeds on top of it using the paper towel method:
Games Console
PC / Laptop
Modem
It is important to be able to trap moisture in around the seed. A high humidity will give the seed enough water, and air. Along with the warmth, your seed with be showing signs of tap root within 24 hours.
Humidity Domes
If you are planting your seeds straight into the medium, then you can use humidity domes to trap in the moisture. They are simply placed over the top of your seeds, where they are planted in the pots.
Plastic cups can also be used, but they should be see through. You still want light to be able to get to your plants.
Lighting
Your seedling will not need light, until it has shot out of the surface, and began to grow its first set of leaves.
A seedling will not need a lot of lighting. CFL or T5 fluorescents are used for the first week of a seedlings life.
Too much light can stunt the growth, use a low intensity light for the first week of growth, and gradually increase wattage as the plants grow bigger.
Nutrients for Cannabis Seedlings
Inside of a cannabis seed, there is stored a few days worth of food for the seedling to eat, whilst it pushes out its tap root, and first shoot. When these stores are used up, you will have to make sure nutrients are available to your plant.
If you’re growing in a hydroponic system, you will need to add a small amount of nutrients to your medium. Start off very low, with 0.2 EC over your background EC.
You should be using “grow nuits” all the way from seedling, through veg, and up until flowering.
If you are growing in soil you should use a potting mix for seedlings. Soil will have a certain amount of nutrients in the medium, before you add any. This can be very strong for seedlings, and it can kill them.
Use a potting mix, or mix the soil you intend to use with 50% coco.
Germinate Cannabis Seeds
The older a cannabis seed is, the harder the shell will be. To soften this shell, most growers will soak their seeds in water for up to 24 hours, before they begin to germinate them.
Soaking the seed will make it easier for the tap root to push its way outwards, and it will also make it easier for water to make its way inside.
Soaking the Seeds

Soak the seeds for 24 hours at the most. Check on the seeds every couple of hours to see if any sink to the bottom of the glass.
When a seed sinks, they can no longer get air, and they will drown. Check regularly, and when they sink, move them onto the next step, the paper towel method.
The Paper Towel Method
The paper towel method is the most commonly used technique to germinate cannabis seeds.
After your seeds have been soaked, you will need to prepare some things before moving the seeds onto paper towels:
- 4-6 Paper Towels
- 2 x Plates or Saucers
- Water
- Cling film/ Plastic wrap
Wet a paper towel (or 2, depending on how thick the towels are), so it is wet, but not dripping with water, place this on top of one of your saucers.
Next, place your seeds, around the paper towel on top of the plate. Space them out evenly, and then cover them, with another paper towel.
Lightly wet the paper towel that covers the seeds, and then, turn your second saucer upside down, and place it over the top of the seeds like a dome.

Wrap the saucers in cling film, so that no moisture can easily escape. Now, you have to store it in a warm place, like your heated propagator, modem, or games console for 24 hours.
Check on the paper towels after 8 hours, just to ensure they have not dried out. If moisture is escaping, then the towel may dry out. This will cause the seed to dehydrate and die.
After 24-48 hours, you should see the seed is cracking, and a tap root is forming. This is a good time to plant your seed into the medium.
Planting Cannabis Seeds
Some growers will soak their seeds, and then go straight onto planting them, others will crack the seeds open with the paper towel method before planting. There are many way to germinate cannabis seeds.
Planting your seeds straight into the medium after a few hours of soaking is fine. But using the paper towel method will increase your chances of germination.

Place your small pots, into a propagator, or place humidity domes over the top of them. Locking in the moisture will again improve your chances of successful germination.
Propagation and Environment
Keep your pots, with your seeds in them, in a dark place, at around 21°c. Keep the medium damp, do not let it dry out. Humidity needs to be above 65% for the best chances of germination.
It can be tempting, but do not disturb the seed, or the soil around it. It can take up to 7 days for the shoot to emerge from beneath the medium. Just be patient.
Usually, within 3-5 days, a green shoot will start to grow. This is when the seedling stage begins, and you have successfully germinated a cannabis seed.
First Growth of a Cannabis Plant
As soon as the plant starts to show above the surface, you will need to provide it with light, and a slight breeze. It can be a week before the seedling will grow its first set of true cannabis leaves.
The Shoot
The shoot will emerge and quickly start to grow upward towards the light. If the light is not sufficient, the seedling will stretch towards it, and the stem will become too tall, and will not be able to support itself.
Lighting and Light Cycle
Using a T5 fluorescent or a CFL for the first week of the seedling stage is a good idea. Not only are they low on energy costs, but the light output will not be too much for the plant.
Run a T5 or CFL for the first week, on either 24 hours a day, 20 hours of light with 4 hours of darkness, or, the standard 18/6.
Temperatures and Humidity

Seedlings like a slightly cooler temperature than a fully vegetating plant. You are trying to imitate the natural spring environment for your baby cannabis plants.
Temperatures should be around 22°C when lights are on, and no lower than 18°c, when lights are off. Humidity should be easily manageable with humidity domes or a propagator in these early stages. Keep humidity around 65%.
Feeding schedule
If you are growing in soil, your soil already have plenty of nutrients in it. In some cases may even be too strong for a young plant.
Use a potting mix, or mix your soil with some coco to reduce the EC of the medium. This can help small plants adjust to the medium, without being shocked by the amount of nutrients in the soil.
For hydro growers, check your background EC. Add some grow nutrients to the water, to increase the EC by 0.2 points. This will keep your plant happy for the first week.
You can also use CANNA Rhizotonic during the first week of growth. It will provide the plants with everything it needs to build a strong happy root zone.
Rhizotonic can be used in soil, coco, or full hydro setups. It will provide the roots with amino acids, microbes, and much more, and will give your plant a great start to life.
Along with root stims like Eco Thrive and Great White, your plant will be needing a transplant into a bigger pot within the first 2 weeks.
Repotting and Transplanting
When the roots of your plant are starting to outgrow the pot they are in, it is time to transplant them into a bigger pot.
This could take a couple of weeks, but when the roots start growing out of the bottom of the pot, it is a good idea to transplant.
Repotting
When the roots grow out of the bottom of the pot, it is time to move the plant to a bigger one.
The vegetative stage should be started in a 3-5L pot, and transplanted again later into veg if needed.
For soil growers, transplanting is also a great way to bring more food to your plant, without having to add any extra nutrients.
The extra soil in the new pot, will have more nutrients in it. So the roots will spread out, and use these.
Moving into Veg
After germination, a week of seedling stage, and a transplant into a bigger pot, your plants are ready to head in the vegetative stage. This brings you to the end of germination. The plant will now grow very quickly, and will build stems, branches and leaves, preparing itself for the flowering stage.
Lights should be kept on for over 18 hours a days, with 18/6 being the prefered cycle by most growers.
Final notes on Germinating Cannabis Seeds
This guide can simply be put into three easy steps, soak the seed, plant it, and wait. Most of the time, the seed will pop within a week. But to increase your chances of a successful germination, you should use the techniques above.
Thanks for reading! You can find more information on anything related to growing in our cannabis grow guides. All of our guides are written by experienced growers, and members of our cannabis growers forum. If you have any questions, sign up. It is free, and we are always happy to help!
I was talking to a cannabis cultivator out of Israel. He soaks his seeds too, but overnight in one pint of water with 30 ml of 3% H202, hydrogen peroxide.
I also learned why I had a hard time germinating in rockwool. My ph was at 5.8-6.0. Another friend informed me rockwool ph drifts up. Seeds don’t like it. I ph my soaking mix at 5.5. The seeds like it a lot. 80 F seems to be good on my seed mat thermostat.
Good luck!
@percysgrowroom
Such an amazingly in depth guide. Thank you grow team!
Overjoyed to find out soaking seeds is exactly what it says on the tin! 💪
@ikkinuggets I would use it at 100% TBF mate, and just watch the height to make sure its not too close.
@percysgrowroom
I bought this 30W LED for houseplants some time ago and was wondering if it would be sufficient for starting my seedlings. I’ve read the guide and see that CFL or T5 fluorescents are recommended but I’d like to get away with using what I already have.
The light has 5 dimmable modes (20%, 40%, 60%, 80%, 100%) and 3 spectral modes (red, blue, and mixed light)
After germination my seeds, would this be sufficient to put them under lights and gradually increasing the percentage? If so, how often would I want to increase the light intensity?
Thanks in advance!! This is my second grow but my first one from seed.
great guide again, fair play bro.
Yes, same method for all seeds regardless of breeder/seedbank
Thanks for the info 😁
Very well explained & presented. Thank you.
What an excellent guide. I used to hate germinating my seeds, but I now find it the most exciting part. I’ve recently followed this guide precisely how it’s documented and my little plants are further on than they’ve ever been. Brilliant stuff.