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.
When the seedling stems reach two to four inches in height, it’s time to transplant your cannabis into larger pots with more room for roots to spread down and out. After you’ve done this, you’ve successfully germinated your cannabis seeds into proper, young plants.
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
When a seed enters an environment with enough moisture, it will increase in size and slowly break out of its shell. A seedling or germ forms from which roots will emerge, helping the baby plant absorb nutrients from the soil. Seeds naturally develop roots facing down and stems stretching upward, allowing the young cannabis plant to simultaneously feed off light and earth.
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.
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.
Monitor your soil every day and keep it moist. Within four to seven days, you should see tiny stems sprouting from the soil.
Soil is an easy, more natural method with which to germinate your cannabis seeds because the soil protects the fragile roots from any interference. Photo by: Gina Coleman/Weedmaps
Germination itself is a crucial aspect of cannabis cultivation. The seed germination process is the foundation of every marijuana plant, and steps can be taken to boost successful popping. For example, some cultivators improve germination attempts by soaking seeds in 1% hydrogen peroxide or a compost tea for 12 hours beforehand to kill any dangerous pests.
Even if your seed sprouts fast and grows vigorously, it still has roughly a 50/50 chance of being female and producing buds, instead of turning out to be a male.
Once you see the taproot, it’s time to transfer your germinated seed into its growing medium, such as soil.
Autoflowers don’t need lots of nutrients because they’re small and don’t spend much time in the vegetative cycle. They won’t need as much veg nutrients—such as nitrogen—but will need more bloom nutrients.
Males will have round balls—these will develop into pollen sacs, which will release pollen into the air when mature.
Time to germinate
Growing marijuana takes a certain level of commitment: time, energy, and financial resources, so be sure you can commit to the whole process.
Finding a cannabis seed in your stash is not ideal, but we’ve all been there before. Although much less common than it once was, it still happens. Sometimes you’ll notice one when grinding down some flower, or you’ll see one pop, spark, and crackle from the heat of a lit bowl.
CBD, or cannabidiol, is one of the chemical components—known collectively as cannabinoids—found in the cannabis plant. Over the years, humans have selected plants for high-THC content, making cannabis with high levels of CBD rare. The genetic pathways through which THC is synthesized by the plant are different than those for CBD production.
You might also find a mature seed that has been physically damaged through poor handling, like rough trimming. In those cases, it probably isn’t worth the effort to try and germinate the seed.
Plants grown from seed can be more hearty as young plants when compared to clones, mainly because seeds have a strong taproot. You can plant seeds directly into an outdoor garden in early spring, even in cool, wet climates.
Your seedlings might need to be watered if:
Water from below, not above, to ensure that you don’t squash the seedlings. Make sure your seedlings aren’t sitting in water, or you’ll have issues with rotting, fungus, and soil gnats.
You can also use Eco-friendly Seed-starter Cowpots, which you eventually plant into the ground, adding nutrients and organic matter to the soil.
Don’t use incandescent light, use fluorescent. Full spectrum bulbs include both red and the blue light, or you could use one warm (red) light and one cool (blue) light.
Your seedlings will need light, but they also need periods of rest (darkness) too. A good rule of thumb is to turn the grow lamps off when you go to sleep, and turn them on when you wake up (or use a timer). Read all about different types of grow lights here.