In this guide, we will walk through a simple and reliable method to germinate cannabis seeds, using peat moss pellets or plugs.
In tropical conditions, cannabis seeds germinate in the warm rains of early spring. The well-drained soil of the forest floor wouldn't be waterlogged, but it wouldn't dry out. The ideal temperatures would be between 70°F-80°F (21°C-26°C), with 60-80% humidity.
Peat moss pellets are pucks of dried peat moss enclosed in a fine netting. As a mostly inert medium that retains water well, peat moss pellets do a great job of mimicking the natural conditions of spring jungle floor.
What you need
- Peat moss pellets: Get them online or at local department/hardware store - they are widely available.
- Filtered water: You probably have this in your fridge. pH balance between 5.5 and 6.5
- Cannabis seeds
Step 1 - Flood the Peat Moss
Peat plugs come dried and compressed, so we need to flood them with water. Use some warm filtered water from your fridge, rainwater, or distilled water that's pH balanced between 5.5 and 6.5. Add water until the plugs are saturated, then drain the excess water. The plugs will swell 4-5x their original volume.
Step 2 - Insert Seed
Most plugs or pellets have a small hole in the top. Insert the seed between 1/4-1/2" (6-12MM) deep and lightly cover with an excess medium.
Don't have seeds or curious about what strain to grow? Learn all about strains and how to buy seeds online in our seed guide.
LifeProTip: Label your plants! All emerging seedlings look identical, and most mature plants look very similar. If you start multiple strains at once, make sure to label them. Plastic plant labels can be fixed to peat moss plugs to identify the plant through its life - adding dates makes it a self-contained record.
Step 3 - Wait for it!
The next few days is mostly a waiting game. Put the pellets in a partially covered container to prevent drying out and follow these two simple rules:
DO keep the pellets warm and moist throughout germination, cannabis seeds germinate best in these conditions.
DO NOT flood or over-saturate the pellets after the initial flooding, since this will prevent the roots from getting enough oxygen. Too much water and the seedling will 'damp out' and fail.
One easy method to ensure that you get the right amount of water is to use a spray bottle to wet the outside edges. Another is to quickly dip the bottom of the pellets into the water; moisture will wick upwards to the rest of the pellets. Either method will encourage roots to grow outward.
Check the pellets daily, and you should start seeing signs of emerging seedlings after a few days. It may take a few days for the plant to shed the seed hull and figure out which direction is up.
Step 4 - Care for it!
As your young seedling emerges from the seed, you'll notice that it has a set of 'built-in' leaves that don't look a lot like pointy cannabis leaves. These are the cotyledons, and they are there to help the young seedling bootstrap the photosynthesis process. Young seedlings need light right away - but not too bright for the first few days.
Head on over to the Seedling Care Guide to learn how to take care of your seedling.
Optimizations & Alternatives
Germination Heat Mats
Germination heat mats are just like heating pads, but they don't get as hot and are water resistant. These are especially useful for germinating seeds in colder conditions.
One of the best ways to simulate the tropical climates is to use an enclosure to conserve moisture and heat. You can make your own from cheap plastic containers, or buy a special purpose kit made for peat pellets. Used along with a germination heat mats, you can easily set up a tropical jungle climate anywhere.
Can I germinate pot seeds directly in the growing medium?
Yes. Use a solo cup sized container filled with soil or coco and place the seeds about 3/4 inch (~ 2cm) deep. Keep the medium moist but not wet until you see the seedlings emerge between 3 and seven days later.
Can I germinate cannabis in paper towels?
Yes, you can germinate marijuana seeds in moist paper towels. While this approach might be slightly faster than the other methods we've shown here, we don't use this method because of the risk to the plant and main root during transplanting.
How long does it take to germinate?
From the time that you place your seed into the germination medium, you should start to see the emerging seedling within 2-5 days. Germination is usually complete, and the plant is a young seedling within seven days.
Should I germinate with nutrients?
Germinating plants don't need any nutrients; it can burn their new leaves and roots. That's why its best to grow seeds in an inert medium, like a peat moss pellets or a paper towel. Young seedlings don't need nutrients until they are a few weeks old.
Do cannabis seeds need light to germinate?
Not really, but they need light within the first day or so of emerging from the seeds, so it's a good idea to germinate with a light source. Sunlight, fluorescent or low powered LED grow lights are all great options. You can learn all about lighting options in this guide.
Alternative to peat pellets?
Many farmers use rock wool cubes for starting clones and germination, particularly hydroponic growers. While these work well and are economical, they come with drawbacks. We recommend that new growers begin with peat pellets.
What if the seed gets stuck on the seedling?
They usually loosen and come off after a day or two. If it doesn't come off, you can try to separate them with tweezers gently.
When is it time to plant the seedlings?
You'll know when its time because roots will be busting out of the bottom of the peat pellet, like in the picture below. Plant the pellet in a solo-sized container using a quality soil mix. You can learn more about containers and how to transplant here.
Next up: Learn how to care for seedlings
Learn how to create an environment your seedling can thrive in,