You can also germinate your seeds by placing them in water. It’s slightly faster than the soil method, but you need to adjust your environmental factors accordingly. Remember, successfully germinating seeds requires a perfect balance of ideal growing conditions. When germinating in water, seeds need only 24-48 hours to pop their stems, though cultivators can keep them soaking for up to a week as needed. Water germination is faster because the seed gets all the moisture it needs immediately, and the shell softens and cracks more easily after soaking.
The environment in which seeds germinate also plays a role in the outcome. While there are several different germination methods, each requires proper moisture, minimal handling, and warm springtime temperatures between 68-72 degrees Fahrenheit.
First, make sure you use the correct type of soil, either gently fertilized potting soil or a seed starter with a pH level of approximately six (6). The soil contains the right acidity and enough nutrients to strengthen your young cannabis plants for the first two weeks. Be careful not to add more nutrients, or you risk overfeeding and killing your seeds.
Whether you’re planning an indoor cultivation or outdoor grow, it’s best to germinate your seeds indoors. It’s easier to maintain proper temperature, light exposure, and moisture inside, and you can protect your seeds from the elements. Indoor germination, whether using soil or paper towels, will ensure your cannabis seeds have the best chance for survival.
Lay one paper towel on top of a countertop, place a few seeds, and cover them with a second paper towel. Photo by: Gina Coleman/Weedmaps
Use a spray bottle to moisten the paper towels and then store the cushioned seeds between two plates, under a face-down bowl, or gently place them in a plastic bag. Maintain a temperature of about 72 degrees Fahrenheit, keeping the paper towel wrapped seeds in the dark and away from a windowsill. In two to five days, the seeds will pop inside the paper towel sandwich and emit tiny roots, ready to plant when they reach about five millimeters in length.
The downside of water germination is that once they’ve popped, you’ll need to maneuver them into their growing medium manually. This is a delicate process, as germinating seeds are extra fragile, and any harm risks the development of your plants. Make sure to place the seed roots down in the soil when you transfer to a pot.
You don’t want to load your plate up with tons of paper towels, but it’s nice to have several sheets so they can hold plenty of water. If necessary, fold or cut the paper towels to size so everything fits completely inside the plate. If a paper towel is sticking outside the plates, everything will dry out quickly.
Cut Rapid Rooters in half to make it easier to insert germinated seeds
1.) Put 3-4 Layers of Paper Towels on Plate
Seedling heat mat to keep seedlings warm (or any surface that’s about 70-85°F or 20-30°C)
I recommend cutting your Rapid Rooters in half to make it easier to place germinated seeds. Even a seed with a long wiggly root will usually easily fit into the “crack” of the Rapid Rooter. This prevents you from bending the roots.
If the seedling has already lost the shell, place the leaves close to the top. These seedlings often grow the fastest.
The taproot of the cannabis seeds will begin to grow longer. As it grows longer the seed will get pushed upwards. Eventually, the shell of the cannabis seeds will push up through the growing medium you have used. The first leaves are known as “cotyledons” and they will begin to appear soon.
Marijuana seeds germination best practices
Germination should take place in around 36 – 96 hours if all goes well. Some of the seeds will germinate quickly whereas others might take a bit longer. Often older and weaker cannabis seeds take a bit longer to germinate.
12 – 24 hours should be plenty of time for your seeds to soak.
Keep it moist – Make sure that the cannabis seeds are kept moist but not soaking during the germination process. On average you should soak the seeds for 24 – 32 hours. They shouldn’t be left to soak longer than that. By keeping them wet and not moist you could actually drown your seeds.