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how to sex a marijuana plant from seed

Often, growers will top, or cut off, the stem after about five nodes, which forces the plant to grow out laterally more, creating more bud sites.

Mycorrhizae, a beneficial fungus, can be added to soil to improve root systems.

Cotyledon leaves

Males and females are usually only pollinated when crossbreeding plants or creating new strains.

Sugar leaves are the small, resin-coated leaves that buds form around. Sugar leaves are usually saved as “trim” during harvest and can be used for pre-rolls, extracts, and other cannabis products.

Cannabis is a dioecious plant, meaning it can be male or female, and the male and female reproductive organs appear on different plants. What’s in your stash jar now are the flowers of a female marijuana plant.

Okay, back to sexing cannabis.

Why grow regular cannabis seeds? Well, maybe a particular breeder or strain you want to try only carries regular seeds. Some growers feel that the feminization process is unnatural, and prefer to kick it old school by growing regular seeds only. Some enjoy the gamble and challenge. Whatever the reason, when you grow cannabis from regular seeds, the odds of getting all lady plants are not in your favor. You will end up with some males. Therefore, you need to learn to sex your cannabis plants! Also, we always start several extra “regular” seeds – assuming a 50/50 chance that some will be culled because they are male.

When to Sex Cannabis Plants

Like most things in nature, female cannabis plants have a biological drive to reproduce. After the deed has been done, she will sit back and relax. While a pollinated female cannabis plant WILL still develop decent size buds, they are usually lower quality and contain less THC and other desirable cannabinoids. Not to mention, they’ll be full of seeds. When left un-pollinated, a female cannabis plant’s flowers (buds) will continue to swell, develop more trichomes and become increasingly resinous. She is trying to get as sticky and large as possible to catch pollen in the wind. That sweet sinsemilla – aka unfertilized, seed-free cannabis.

I hope you started a few extra seeds, and have plenty of ladies left to grow! Once you determine that you have a male cannabis plant, get rid of it. Again, unless you want pollination and seeds, it is best to cull the males as early as possible. Simply separating the plants isn’t enough. Even if you relocate the male plant to another part of your yard, the pollen can carry in the wind. There are stories of female cannabis plants becoming pollinated from neighbors growing several blocks away.

Keeping in mind that every strain and grow set-up (e.g. indoors, outdoors, daylight hours) creates varying circumstances, most cannabis plants begin to pre-flower as early as 4 weeks after germination. By week 6, the pre-flowers begin to reveal their gender and you should be able to identify the sex using the tips to follow. Once the plants go into full flower (8 to 10 weeks on average, for a natural outdoor grow) the differences between male and female plants will be glaringly obvious. We’ll talk more about exactly what each sex looks like in a moment.