Sexing Cannabis: Part I Cannabis Physiology

Sexing Cannabis: A three-part series from cannabis physiology and physical differences between sexual organs, to tips for sorting genders that works best for your medicinal garden.

PART I: Cannabis physiology

Many plants existing in nature are monoecious, which means they simultaneously express both male (staminate) and female (pistillate) flowers on the same plant. Some plants however, individually express male and female sexes separately on different plants within the same species, termed dioecious; among these non-habitually occurring plants is where we find Cannabis. As any cannabis cultivator can tell you there is a time and place for male plants, but ultimately it is the female cannabis plant that is eagerly sought after due to her medicinal fruit bearing qualities. To help growers navigate the sexual properties of their plants, we are introducing a three-part series on the Bounty Blog that will explore all the steps involved with sexing plants in your medicinal gardens. In Part I: Cannabis Physiology, we will explore the basic sexual makeup of cannabis plants. Part II: Physical differences between male and female cannabis plants will provide you with some visual references that can help you best determine which plants should remain in your garden. The last segment, Part III: Tips for sorting genders: which method works best for your medicinal garden, will be a great resource for any grower wondering how to best assist plants in revealing their gender.

Cannabis, like all annual fruit bearing plants, is genetically inclined to reproduce in order to continue its genetic lineage, and while these female plants are able to self-pollinate under certain circumstances, they crucially rely on males for pollination to continue the species. However, if females go un-pollenated throughout their entire life cycle, known as Sensimilla- Spanish for “seedless,” they are able to focus their time, energy, and growth hormones toward the production of pistillates, female organs, and trichome glands. Sensimilla girls will mature to produce prolific amounts of flower-spears known as “colas,” which store abundant amounts of Delta 9 Tetrahydrocannabinol (THC). THC is a pharmacologically-active organic compound not directly involved in growth, development, or reproduction of the cannabis plant itself, but instead acts as a defense mechanism against herbivores in nature. Many advocates looking to extract the pain-relieving and healing properties of THC are cultivating marijuana to provide medicinal alternatives for patients in need. If ever pollinated however, the female then invests its energies in producing seeds/off-springs, in turn significantly decreasing consumable cannabis and potency in medicinal values. For cultivators this means that being able to determine sex during pre-flower is essential in maintaining a uniformed sensimilla garden relieved of lurking males prior to pollination. This ensures that the medicine provided to patients is of the absolute best quality.

Even though cannabis plants are fundamentally either male or female, they do have the ability to turn hermaphroditic- i.e. female cannabis plant can grow male sex organs and produce pollen and male plants can grow female pistils. Female plants that grow male sex organs can pollinate themselves and other nearby females, inducing a production of non-viable seeds which degrades the quality of harvestable cannabis. Hermaphroditism can be triggered by stress, chemical treatments, erratic light cycles, or by genetic predisposition. Even pure female plants have the potential to turn male or hermaphrodite. This is often seen near the end of flowering when stressed-out, unfertilized females produce one or two male flowers in a vain attempt to continue the species.

In nature most plants are pollinated by insects attracted to brightly colored flowers; in the case of cannabis, female plants become pollinated by pollen carried in the wind. The wind can spread pollen for miles and a single male can produce enough pollen to pollinate thousands of female plants within several hundred feet of proximity. This makes the presence of a boy dangerous for both in outdoor and indoor gardens unless you intend to breed.  So how do you separate your boys and girls in your garden? What physical characteristics do you need to look for? Check back with us during PART II: Physical differences between male and female cannabis plants to find out how!