Plants can hermaphrodite (hermy for short) for a variety of reasons. For example, an interrupted light cycle or extended exposure to a light leak will cause male parts to protrude from clusters of calyxes. These small male parts, which resemble miniature bananas, will release pollen if the flowers are allowed to mature. The pollen is caught by the trichomes on the pistils and a seed is formed in the calyx. While the seeds are growing, nutrients and energy that would otherwise be used for bud production are instead being used for the production of seeds. Depending on the strain being grown, the seeds will change in color from a paler shade of white to a richer shade of brown or grey. The bud of the hermaphroditic plant is still usable for medicinal purposes; however, expect the THC, CBD and CBN levels to be much lower because of plant energy needed for bud production that was consequently lost. Uninterrupted by male flowers, the calyxes will swell with resin and will produce what is known as sensimilla (without seeds).
You begin any grow cycle by taking all necessary precautions to prevent hermaphrodites from arising. However, if you have already noticed male parts, you can still take steps to eliminate the pollinating flowers. The first step is to use a small pair of scissors to snip the male flowers at the base. While cutting the flowers, it is wise to either cover the plant gently with plastic wrap, or hold plastic wrap around the male part you are covering. This avoids accidentally releasing more pollen onto the calyxes, depending on the maturity of the male flowers. While this method may not eliminate all of the male parts on your plant, it will slow the process and lessen the damage. Remember to keep the light schedule on a strict pattern and avoid light leaks to avoid further hermaphroditic changes to the plant.
Finish your grow cycle and, if you are lucky enough, your plant will mature with mostly sinsimilla bud production, and possibly a few seedy buds at certain internodes where it may have been hard to remove male flowers without spilling pollen. Also, it is important to keep hermaphroditic plants away from flowering female plants, as they can be easily pollinated. Lastly, it is common for certain marijuana seeds to develop male flowers toward the end of a grow cycle. This is thought of as a method of verifying maturity, along with checking the color of trichomes on calyxes with a 30x or stronger scope for a cloudy to amber color, depending on your personal preference for THC, CBD and CBN levels.
With the right techniques and preparation, you can perform a medicinal marijuana grow that produces a sinsimilla crop. However, in the event a hermaphroditic plant arises, using these methods to remedy the male flowers will ensure that you are doing the most you can to retain the female flowers without danger of pollination.