Among the early signs that your female has been pollinated is that her bracts become larger. Bracts are small, leaf-like structures that protect the female’s reproductive parts. These are the sites from which the flowering buds appear. Do not confuse the bracts with calyxes.
To determine the sex of your cannabis plants, you will have to wait until the pre-flowering stage when plants begin to put their energy into reproduction. Female cannabis plants show their gender signs later than males. At the location where they will soon grow their buds (the nodes between the stalk and the stem), females will show wispy white hairs.
HOW TO AVOID POLLINATION OF YOUR FEMALE PLANTS
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.
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.
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.
Male plants literally have grape-sized “balls” of pollen. The balls will show up about a week or two after the plant has entered the flowering stage. They also produce a growth that is a distinct yellow colour and look a bit like bananas.
Cannabis plants are monecious. This means they have the ability to be either male or female. Or in the case of hermaphroditism, they can be both. The reason to make sure there are no males or hermaphrodites in your garden is because male flowers make pollen. When pollen touches the white hairs on a flower, it makes a seed, and seeded weed gives you headaches. Even though there are reasons in nature hermaphroditism could be important, such as continuing the species in case there is no male present, hermaphroditism is generally a bad thing when talking about cannabis plants.
There is only one more problem. Cannabis plants can be both male and female in the right circumstances.
WHEN DO CANNABIS PLANTS SHOW GENDER?
Cannabis is actually much like other plants – with most having this ability. In essence, female plants have the ability to develop male characteristics. This usually occurs thanks to environmental stress. Plants will develop male characteristics at a certain point in the grow cycle in an effort to ensure seeds are produced before the stressor can kill the plant.
Light poisoning is the most common cause for a normal plant to hermaphrodite. Light poisoning refers to the flowering night cycle of a plant being unnaturally interrupted with light. The best way to prevent this is to close yourself inside your darkened room during the daylight, and then after allowing a few minutes for your eyes to adjust to the dark, check for any light leaks from covered windows, door jams, etc. Also cover all timer and appliance lights with tape.
I have an indoor growroom and in my recent harvest I found seeds in the buds, but I’m sure there are no male plants in the room. I’ve heard that light leakage can cause plants to become hermaphrodites. Is this true, and if so, do you have any tips for avoiding this?
Female plants take a bit longer than males to show signs of gender after flowering. The plants begin to develop a few wispy white hairs where the buds will soon grow. These flowers begin to form between the stalk and stem. Female pistils are always white (never green).