Soil is an easy, more natural method with which to germinate your cannabis seeds. The soil protects the fragile roots from any interference, and soil is, after all, where a cannabis plant would grow in the wild.
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
How to germinate cannabis seeds
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 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.
Gently water the soil with a spray bottle and situate your pots under a fluorescent lamp. Keep seeds away from the windowsill, as the temperature is too volatile for germination. In general, you’ll want to keep the temperature in the range of 70 to 80 degrees Fahrenheit.
New seedlings should be given access to bright light from the time they emerge. Care should be exercised in the first week or two, as seedlings are still quite delicate.
This article explains how to correctly germinate your cannabis seeds, covering everything from optimum temperatures, to potting your seedlings and transferring them outdoors (or inside under lights).
Within a few days some or all of the seeds should open and put out a root. It is common for cannabis seeds to open within 72 hours of being put in the germination medium. Less commonly, some seeds may need up to 10 days or even two weeks to open and put out a root.
Step 3. Potting – How to germinate cannabis seeds
Make a hole in the growing medium that is about twice as deep as the seed is long, so that each germinated cannabis seed sits 2-5mm below the surface.
Line the bottom of the first plate with a few layers of wet tissue and drain any excess water from the plate.
The best way to germinate cannabis seeds requires only two saucers or plates and some moist tissue. Here is a step by step guide.
Place another few layers of moist tissue on top of the seeds, again allowing excess water to drain off.
If growing male and female cannabis seeds, they’ll start to show their sex organs, or “pre-flowers,” after 8-10 weeks from germination.
Viable or not, there’s only one sure way to find out if a bagseed will grow. If you’re simply curious to learn and not as concerned with the overall outcome, you can plant a couple of bagseeds outside and see what happens.
In some cases, even if a seed isn’t completely mature, there’s still a chance it could be viable. But often these are extremely weak, take long to develop, and express other unfavorable characteristics. Growers usually discard weak plants to free up space.
Transplanting germinated cannabis seeds
Some varieties of cannabis can produce male parts alongside female flowers on the same plant, especially if exposed to environmental stressors. These plants are known as hermaphrodites, and sometimes they can self-pollinate to create seeds.
With cloning, you don’t have to get new seeds every time you want to grow another plant—you just take a cutting of the old plant—and you don’t have to germinate seeds or sex them out and get rid of the males.
There are a few indicators that will give you a sense of whether the seed is worth germinating.
Because they grow and flower quicker, growers can fit in multiple autoflower cannabis harvests into the span of one regular harvest.