The first step in a successful cannabis grow is successfully germinating cannabis seeds. This is the stage when you’ll actually plant the seed and then help it as it starts to sprout. If you want your cannabis plants to be strong, healthy, and ready to produce a good crop of buds, you’ve got to start them off on the right foot. You do that by germinating cannabis seeds the right way.
Method 1: Rockwool
Rockwool is a fibrous growing medium made out of basalt and chalk. It’s used in a lot of different gardening projects, and it’s a common choice for germinating cannabis seeds.
You can use either rockwool plugs or rockwool blocks.
Rockwool plugs are small cylinder shaped pieces of rockwool and they’re great for germinating cannabis seeds one seed at a time. Rockwool blocks are big chunks of rockwool and are perfect for larger scale growing.
Before doing anything else, you need to flush the rockwool with distilled water. Then soak it in water that’s got a pH of 5.5-6. This will give your seeds the perfect growing environment.
When you’re ready to plant, gently plant the seeds .5 to 1 centimeter deep.
Keep the rockwool moist. It should be around 72 to 80 degrees Fahrenheit. The seeds should start to sprout in two days or so.
From there, give the sprouts plenty of light, keep them well watered and warm until they’ve got enough of a root system to be transplanted.
Method 2: Peat Pellets
This is an easy way to germinate seeds, especially if you plan on growing your cannabis plants in soil.
Soak the pellets in water until they’re fully expanded. Then drop the seed into the hole in the top. Cover it with a light layer of peat.
After the seed is in the pellet, be sure to keep the peat moist—it should never dry out. After a few days, you should see a little sprout coming out of the pellet.
Keep the sprout well watered and well lit. When you see roots starting to creep out of the pellet, it’s time to transplant it. The good thing about peat pellets is that you can plant them directly into a larger pot or the ground and they’ll naturally break down as the sprout grows.
Method 3: Biodegradable Pots
There are a bunch of different biodegradable pots you can use to germinate your cannabis seeds. Many of them will actually fertilize the plant as they break down.
To germinate cannabis seeds with this method start out by filling the pot with growing medium. Fill the pot about three-quarters of the way with pre-fertilized potting soil and top it off with seed starting mix.
Get the entire thing moist. Then plant the seed .5 to 1 centimeter deep.
Keep the soil moist but not saturated. When the seed sprouts, continue to care for it until it’s ready to transplant.
Since you’re using a biodegradable pot, you can plant the entire thing directly into the ground or whatever container you plan to grow the plant in.
Before transplanting, you might want to carefully cut the pot open to help the roots more easily grow and expand. But either way, the pot should naturally break down and your plant will continue to grow.
Method 4: Directly In Soil
If you’re going to grow your plants outside in the ground, you can avoid having to transplant anything by germinating the cannabis seeds directly in the soil. This is definitely a viable way to do this, although there may be more risks than germinating the cannabis seeds indoors first.
Before planting the seeds in the ground be sure there’s no more risk of frost. You also don’t want it to be overly humid.
Plant the seeds 1 centimeter deep in well aerated, light, and fluffy soil. This will give the young plant plenty of space to start growing roots. Don’t pack the soil down around the seed.
Keep the seed moist until it sprouts and starts putting out leaves. From there, water the baby plant carefully. Avoid pouring water directly on the stem and try to just get the water directly to the roots.
Don’t drown your young plants, but don’t let them dry out either. Continue this process until the sprout has grown into a young plant.
Final Hit: Germinating Cannabis Seeds
Now that you’ve got four good methods for germinating cannabis seeds, here are some general tips for success. These tips apply to whichever technique you use.
- Be sure the growing medium is light and not too dense. As the seed sprouts, it needs plenty of room to develop a root system. A well-aerated growing medium will allow water to drain so the roots don’t rot and will also let oxygen get to the roots easily.
- Cannabis seeds germinate best at a pH around 6.3 so do your best to give them water with that pH and to keep their growing environment at that level. Learn more about this by checking out our guide to mastering pH levels.
- Young cannabis plants do well with humidity levels around 90%. The easiest way to accomplish this is to use a clear plastic humidity dome while the plants are young.
- Keep the germinating cannabis seeds and sprouts at a temperature of 72-80 degrees Fahrenheit.
- As soon as the seeds have sprouted and they start developing leaves they need lots of light. Check out our guide to lighting to learn the best ways to give your young plants light.