The sex of your plants is genetically determined but is also influenced by the environment. The cannabis plant has two pairs of sex chromosomes, one of which carries the genes that determine sex. As with humans, these are either X or Y. Male plants have the XY chromosome while females are XX. In nature, each grouping has a roughly 50:50 chance of occurring per seed, but in your garden you can control male to female ratios once you learn to recognize what each gender looks like.
Female marijuana flowers, which start to appear later than those of the males, look more like sacks. As they develop, two upraised feather-like stigmas will shoot out of each sack. They are usually white or cream-colored and are generally found on the main stalk at a node region. A node region is the area on a plant where a branch grows from the stem or where a branch grows on a branch. These stalks are designed to trap the pollen released by the male plant and carried along by the wind.
A word about Pollination If a female plant should receive pollen, it will no longer focus its energy on growing flowers, but will instead start to produce seeds. A healthy female plant can produce a lot of seeds, but unless you are trying to breed a particular type of marijuana, seed production will offer you no benefits. For this reason, growers remove male plants as soon as they identify them.
Another reason to remove the males is that this will give your remaining female plants more sun and light, and will also reduce the number of plants you are tending. Male plants are not very good to smoke, but leaving them in the ground (away from your females) is fine, because you can still use the leaves to make potent pot butter.
Male marijuana plants usually start to flower one to four reeks sooner than females. They develop fewer flowers and tend to grow straight up, with flowers developing near the top. The immature first flowers (preflowers), appear at the tips of the main stem and branches. These flowers are usually closed, green, and develop in tight clusters. The main parts of the male flower are five petal-shaped objects that enclose the sex organs. They look like a tiny bunch of bananas. As it matures, each one of these clusters opens to reveal a stamen. Stamens allow the plants to produce pollen that is used for reproduction in the wild.
The best way to identify a male is by looking at the preflowers, the calyx, during the early stages of growth. If the calyx is raised on a small stalk or stem then it is generally a male. lf the calyx is not raised then it is generally a female. Watch these areas closely as they develop to learn the difference.
Removing males from your Growing Site
Uprooting male plants from the ground is one extremely reliable way to eliminate the males from your crop. Simply remove the plant and the problem is solved. The disadvantage to waiting until the males show flowers at your site is that you may not notice them until they have already released their pollen. Although a female plant can continue to flower while it is producing seeds, only the healthiest ones will succeed at doing both.
Another method of growing only females is to screen them when they are very young-before the have been transplanted. This requires forcing them to flower at a young age by controlling their exposure to light but only works with mature plants that are capable of displaying sex.
When your seedlings have grown to about one foot in height they should be mature enough to begin the process of forced flowering. This means systematically depriving them of light for a minimum of 12 hours per day. Soon flowers will have appeared at the nodes, or joints. It should be apparent which flowers are males and which are females.
Remove the male plants, and select the strongest healthy female plants to be transplanted to your growing site. Before moving them outside, give the plants at least three days of continuous light. This will stop the plant from continuing to blossom-you do not want your females flowering too early. Once the plant is outside, receiving the long hours of natural sunlight, it will return to a vegetative state, devoting all of its energy to growing taller and stronger.
Both of the above methods will help you limit the amount of seeds or prevent seed production entirely, as well as reduce or eliminate the presence of male plants however force flowering can sometimes cause sexual dysfunction to appear in plants (the hermaphrodite condition where both sexes appear on the same plant - see next section). Choose whichever method works the best for you, and fits within your time and space needs. The problem is that it won't completely eliminate the effect of male pollen. In some areas, male hemp plants, growing either naturally or on farms, may pollinate your plants. Pollen has been known to travel many mites from its source (traveling on birds, bees, or the wind) in search of female plants.
marijuana, being a living organism driven to reproduce, may try to reproduce itself in spite of your efforts. In some cases female plants may grow male flowers thereby attempting to pollinate themselves or the plants nearby. Those plants bearing both male and female flowers are called hermaphrodites.
Hermaphrodite plants that self pollinate tend to produce female and more hermaphrodites. Hermaphrodite plants are worth culling. If you must keep the hermaphrodite then picking off the male flower bunches can be one way of limiting the effect and preventing the crop from self pollinating. Hermaphrodites tend to occur naturally as a response to stress when plants are subjected to difficult conditions such as poor nutrients, excessive nitrogen, cold weather, or force flowering.