Regular seeds have roughly a 50/50 chance of producing male or female plants. Feminized seeds produce only female plants (about 99% of the time). Both are photoperiod-dependent — they start flowering based on daylight hours. Autoflowering seeds flower automatically at 2–4 weeks old and are always feminized.

Cannabis seeds themselves contain almost no THC and are often classified as hemp, but legality varies by location. Always check your local laws before purchasing or growing.

It is not possible to tell which cannabis seed will produce which sex plant. You can usually determine the sex of a plant once the seedling has been in flowering for 3–6 weeks. Male plants will produce pollen sacs, while female plants will produce flowers.

The best result is reached by first germinating the seeds in a controlled environment, which increases the chance that they sprout well. Putting seeds directly in the ground without germinating them first means a higher chance that some won't come up. Extra light during germination is not needed and can actually disturb the process.

Cannabis seeds can last up to 36 months without the germination rate being affected if kept in a cool, dark, dry environment. If kept dark, protected, and refrigerated, seeds can last up to 10 years, though germination rates will drop as they age.

Seeds are best stored in a dark, cool place. You can store them airtight and put them in the fridge — just ensure they are packed airtight so they won't get humid and accidentally start germinating.