Pollination requires the presence of males or intersex (hermaphrodite) plants, which are females that will also produce pollen. The first thing you want to do to keep the risk of pollination low is to remove as many males or “hermies” as as you can. Especially during the first three weeks of flowering, it’s important to frequently check for possible male specimens in your garden.
A good test to see whether the bracts have swollen is to take a pair of tweezers, grab one bract, and open it up. If there is a seed inside, you have a pollinated plant.
There is a good reason why most growers keep male plants away from their ladies: Pollination from males causes the females to develop seeds. As a result, females focus their energy on seed production, rather than on growing you some fine-quality bud. This seedy and unfortunate final product can be avoided by implementing a few basic techniques.
Obviously, no one wants to smoke seedy weed. When you grow cannabis and learn how to identify male plants and signs of pollination, you can remove these plants to save your remaining females. Likewise, recognising a pollinated female early allows you to start again before it’s too late, rather than finishing a grow that will only result in a poor-quality harvest.
The typical cannabis grower normally doesn’t have a reason to keep males, and will want to get rid of them as soon as they are spotted. Cannabis breeders, on the other hand, may want to keep males along with their crop of female plants. In such cases, the breeder will normally separate the sexes to avoid any accidental pollination. They may grow females in one tent and males in another. When grown outdoors, such as in a garden, the males are often kept in the most remote corner of their growing area, as far from the females as possible. Even then, because of the wind carrying around the pollen, there is always some risk of accidental pollination.
Pollination of your female cannabis plants will make them produce seeds and spend less energy on producing quality buds. But when you recognise the signs of pollination early, you can avoid putting time and resources into a poor harvest.
Spotting male cannabis plants and pollinated females early can save you from investing further time and effort into an entire growing season that will be for naught. Most of the time, the best course of action is to get rid of the males along with your pollinated ladies and just start a new grow.
Male plants won’t show hairs at these nodes, but will develop little sacs of pollen. These pollen sacs will look like little balls. These balls can appear on their own or in clusters, depending how far into the pre-flowering stage the plant is. At some later stage of growth, the pollen sacs will burst open, spilling the pollen and possibly pollinating your females.
Another indication of pollination can be the colour of her pistil hairs. When a female has been pollinated, the previously white hairs will soon shrivel and become darker.
Learn about the process of pollination and why you should avoid pollination of your female plants at all costs.
I tend to set my timer in flowering to shine line from 7pm-7am. This gives me time to check on my plants at night when the lights first come on, and I can also check them quickly in the morning before I go to work. It also keeps things cooler since the lights are on at night. Some people (like myself) also get discounts on electricity that’s used at night. But ANY 12 hour dark period will work, as long as you prevent your plant from getting light leaks during their “night.”
Male plants have grape-like balls which form and fill with pollen. The balls will first show up a week or two after changing the plants over to the flowering stage. If the male is allowed to continue growing, eventually these pollen sacs will burst open and spill pollen everywhere.
So all strains of cannabis that respond to light in this way (where the light period effects what stage they’re in) are called “Photoperiod dependent” strains.
“Auto-flowering” marijuana strains pretty much ignore how much light they get each day. Generally you don’t run into these unless you buy them particularly from a cannabis seed bank.
Learn more about auto-flowering cannabis strains
- 18-6 – 18 Hours Light / 6 Hours Darkness each Day
- 24-0 – 24 Hours Light / 0 Hours Darkness each Day
- Flowering – Indoor cannabis plants on this light schedule will start growing flowers (buds)
- 12-12 – 12 Hours Light / 12 Hours Darkness each Day
* Most indoor growers use a timer to turn their lights on and off automatically.
These male pre-flowers are basically immature pollen sacs. When the plant starts flowering, they will grow and turn into bunches that almost look like grapes.
Regular marijuana seeds will be 50% male, and 50% female. That means half of the seeds will be unusable as far as growing buds. One way around this is to purchase feminized seeds online. These seeds are available from all reputable online seedbanks, and the plants produced by these seeds are always female.
After spending a long time in the vegetative stage – some strains/plants will show preflowers (pistils for girls and “balls” for boys) during the vegetative stage if they grow old enough, even when they are constantly kept under a vegetative light schedule. For example, clones can come from plants that are several years old, so you’ll see a lot of clones have female pistils showing, yet will not continue to flower any more than that until after they’ve been switched to a Flowering (12-12) light schedule. Otherwise, all remaining plants will reveal their gender in the first 1-3 weeks after lights are switched to 12-12, and plants enter the flowering stage of life.
It’s easier to ensure the plant gets the 12 full hours of darkness each night when the start and end time for your lights to turn on and off is exactly the same each day. This is why most growers end up getting a timer to turn their lights on and off automatically.
Male vs Female Cannabis Plants Marijuana Life Stages & Cannabisplant sex Yes, marijuana plants show gender, and the cannabisplant sex matters a lot to the grower. That’s because only