We hear this question all the time from clients and beginner growers, and the answer is a resounding no. There is simply no way to tell the sex of a cannabis seed just by looking at it.
Immature cannabis seeds, on the other hand, tend to be green and have a soft outer shell that breaks when any kind of pressure is applied to it.
Growing Seeds From A Bag (Bagseed)
A solid way to obtain great seeds is to find a reputable seed bank. These companies pride themselves of their breeding skills and make sure that their customers receive exactly what has been advertised. They have reputations to cater to, so delivering anything less would only harm their image.
It’s important to only conduct this test if you are planning to germinate the seeds immediately afterwards. The viable seeds that sunk to the bottom of the glass will have taken in water, crossing the membrane of the seed and signalling that it’s time to come to life—activating germination.
Some smokers might be pleased to see some cannabis seeds in their bag, and might think themselves lucky. However, finding seeds in a bag is bad for various reasons. For one, this means the grower has messed up and allowed their female plants to be pollinated by an invading male. When flowers are pollinated, they stop producing THC-containing resin and divert their energy toward producing seeds. Secondly, the seeds will have added to the overall weight of the bag, which means less weed for your buck.
However, potency in autoflowering varieties has increased significantly since their initial introduction, with some breeders crossbreeding the low-THC ruderalis with other more potent varieties.
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.
If growing male and female cannabis seeds, they’ll start to show their sex organs, or “pre-flowers,” after 8-10 weeks from germination.
Many marijuana growers start autoflowers early in the season, and at a different time than a regular crop, so keep the season and climate in mind when growing and harvesting—your plants still need warmth to grow, and rain can give them bud rot. Consider growing in a greenhouse to protect them.
Once cannabis seeds are mature, the female plant begins to die, and seeds are either dropped to the ground where they grow into new cannabis plants next spring, or the seeds are harvested for processing into seed oil or food products, or stored so they can be sown in the ground later and become the next generation of plants.