While many plants can be germinated in the ground, cannabis seeds are fragile enough that you should germinate them before planting.
Germination is the process that brings a cannabis seed out of its hibernation period and starts the cannabis growth process. 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. Photo by: Gina Coleman/Weedmaps
How do you germinate seeds indoors?
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.
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.
To germinate seeds indoors, use any of the methods described above. Within a few days, you’ll have popped seeds ready to transfer to a growing medium.
To employ water germination, fill a glass with tap water and let it sit until it reaches room temperature or around 65 degrees Fahrenheit. Add two to three plant seeds per cup and allow them to sit, watching for any changes. Change the water to fresh tap water every two days, making sure it stays at room temperature.
Vegetative plants appreciate healthy soil with nutrients. Feed them with a higher level of nitrogen at this stage.
Two rounded cotyledon leaves will grow out from the stem as the plant unfolds from the protective casing of the seed. These initial leaves are responsible for taking in sunlight needed for the plant to become healthy and stable.
Take meticulous notes on when and how you perform each step, as well as what the weather is like. Other notes can include how much water you give plants, at what intervals, and how much nutrients you give them. Pictures will also give you a better sense of how your plants look along the way.
Harvest happens sometime between September and November. This depends on your local climate, as well as the weather that particular year—one year it could be the end of September, the next, end of October, and growers in the Pacific Northwest will have to pull down their crops earlier than those in Northern California.
Even if growing outdoors, a lot of growers will start their seeds inside under an artificial light to help them through this delicate stage of marijuana growth.
The biggest variability in how long a marijuana plant takes to grow will happen in the vegetative stage—after the seedling phase and before flowering.
Marijuana light cycle: 16 hours a day
Regardless of where you get your seeds from, it is best to give them a slight (and delicate) inspection before planting. Most of the time, all seeds will germinate; however, poor-quality seeds will produce a weaker plant. Unfortunately, that is something you will not find out until well into the vegetative and flowering stages.
To avoid disappointment, seeds that have a darker colouration stand a better chance of germinating, while pale green or white seeds are likely to fail. Even if dark seeds look slightly damaged, they should be planted anyway. There is a good chance they will still germinate, even if the outer shell is somewhat crushed.
WHAT TO LOOK OUT FOR IN CANNABIS SEEDS
Place one sheet of damp kitchen towel on a flat surface. Space your seeds a few centimetres apart before placing the second piece of kitchen towel over the top. You need to ensure both pieces are damp, not wet. Once again, when the white root tips reach 2–3mm, move the seeds (carefully) to soil pots. Use the same guidance found above for planting techniques.
Planting directly into your growing medium prevents having to move seeds when they are at their most fragile. That first root tip is covered with microscopic filaments that are easily damaged. Given that both a cup full of water and moist paper towels are more prone to temperature fluctuations from their environment, planting in soil is a much safer option.
Two or three weeks after germination, your young seedlings should be ready for their new home. At this point you have two options; transplanting them into soil pots, or taking on the challenge of hydroponics. You’ll know when the seedlings are ready to be moved because the root system should start to poke out of the bottom of the wool blocks. As long as the roots haven’t begun to engulf the bottom half of the wool block, they will seek out water and nutrients in their new surroundings and continue to grow downwards.