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.
You can also minimize headaches and avoid the hassle of seed germination and sexing plants by starting with clones.
Cultivating males is important for breeders trying to cross new strains and genetics, but most people growing for buds will want to remove the males.
Can I grow a seed I found in a bag of weed?
Cannabis can be either male or female—also called “dioecious”—but only females produce the buds we all know and love. For reproduction, males have pollen sacs and pollinate females, causing female flowers to produce seeds.
As we’ve mentioned, cannabis is a dioecious plant, meaning male and female reproductive organs appear on different plants.
To create a dark, protected space, take another plate and flip it over to cover the seeds, like a dome.
Seeds can also form in plants with genetic disorders or instability, like hermaphrodites—plants that develop both male and female reproductive parts. Generally, stress and genetic disorders are viewed as bad, so temper expectations with any plant you start from a bagseed.
Maintaining the ideal temperature (between 22–25°C/71–77°F) and moisture for germination is tricky. Leaving seeds out in the open environment or on a windowsill is far from ideal; a DIY climate-controlled cupboard would do a much better service. A warming mat is perfect for maintaining a constant temperature, but it doesn’t tackle the issue of moisture.
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.
If you don’t like the idea of pre-soaking your soil, you can use a spray to moisten the holes before you plant each seed. With enough moisture surrounding your seeds, you can still encourage a root to develop.
PLANTING DIRECTLY INTO SOIL
Start by filling pots with a premium-quality soil that has been soaked in water. Many growers also choose to lace the water with a root stimulator. Make a hole roughly 10–15mm deep. This will be your seed’s new home. Remove the seeds from their packet and place them into the pre-dug holes. Loosely cover the seeds, but be careful not to compress the soil above the seed too much. The root will struggle to penetrate solid soil, slowing plant growth. Lightly spray the top of where you placed the seed so that your growing medium stays moist.
Probably one of the most common methods of germination. The kitchen towel method comes in several iterations. Some growers use cotton wool pads or absorbent pieces of paper. For this guide, we will be using kitchen towel as it is readily available and holds moisture relatively well.
The dome of the plastic container will create your seeds’ own mini tropical climate. If you then place all the components in a temperature-controlled cupboard, you will have created a self-perpetuating supply of moisture—no need to touch the seeds again until they are ready to be transferred to your final growing medium as a young seedling. Using the stone wool block method, your seeds should germinate in one to two days.
3) Shake matchbox for 10 to 15 seconds to scarify the seeds.
2) Remove seeds from the water. Pour water out onto two paper (or cloth) towels on a dinner plate. Fold the towels over the seeds to cover them.
Other Tips for Germinating Cannabis Seeds
1) Set seeds in a matchbox with an emery board or sandpaper on the bottom.
2) Close seeds inside the matchbox.
5) Check moisture level of towels several times a day, watering once or twice to keep them evenly moist. DO NOT LET THE TOWELS DRY OUT! Let excess water drain away freely. The paper or cloth towels will retain enough moisture to germinate the seeds in a few days. Each seed contains an adequate food supply for germination. Prevent fungal attacks by watering with a mild 2 percent bleach or organic fungicide solution.
Jorge Cervantes shares his process for germinating cannabis seeds into healthy sprouts.