No matter what species of marijuana plants you are growing, you will have either female or male plants. Male plants will produce the pollen that will pollinate the flowers of female plants. (See pictures below) Once pollinated the female plants will begin to produce seeds. If you have no male marijuana plants near the females, they will continue to flower and bud, as well as produce THC. These non-pollinated female plants are known as sensemilla, which basically means seedless. Approximately 30 to 50 percent of marijuana plants end up as males.
If you grow your cold weather cannabis plants in the outdoors, you will notice the plants begin to produce pollen and flowers in July. Those who are closer to the equator and similarly warmer climates will notice that the plants will not begin this process until mid-September. The difference depends on the various budding cycles of your specific variety of marijuana. Some species will bud sooner than others making it difficult to give a specific time to cut your male plants. If you are cross-pollinating various strains of marijuana, you might be required to visit your plants weekly from mid-July to mid-September. The ability to quickly identify your male plants is critical to the success and size of your harvest. If you are lucky enough to have had exceptional weather during the flowering stage of the male plants but failed to notice the signs of the flowering process, you may end up with very little herb, and a large quantity of seeds.
Female marijuana plants will generate sizable seedless buds, a large bud riddled with seeds, or a bud with a small handful of seeds. The first outcome can be achieved by removing male plants before any of the flowers begin to open. The second outcome is a result of mistiming the flowering of the male plant. This is catastrophic if you are lucky enough to have a large female plant because you might loose up to 90 percent of any harvest-able marijuana to it's seed production process. This can be used in a positive way to generate an excess of seeds for a future crop rather than being viewed as a total loss. The last outcome occurs once a small handful of male flowers have begun to open and they are all removed before the rest can open.
Hardy marijuana seeds can be difficult to obtain, so if you find yourself with a particular strain you enjoy, it is important to plan accordingly, and have several hundred seeds for future crops. The ability to spot a male marijuana plant is one of the more difficult skills to learn or explain to someone, as it relates directly to the look and growth of the plant during its development. Even the most experienced of growers can become unsure and will have no choice but to wait until the second or third visit to correctly identify the males. During the flowering stage of development, male marijuana plants will have small ball like buds that lack fine white hairs. The female plants will lack the balls that the males have but will have the fine white hairs that the males are lacking. Often times male plants are taller with stout stems, fewer leaves, and sporadic branching. These plants are typically harvested before the pollen can be shed, except for the select few that are kept for breeding. When you attempt to harvest a male plant, more so if it is near a female plant, you want to cut your plant off from the base taking special care to shake the plant as little as humanly possible. This will prevent accidental pollination by previously undetected flowers.