Ever wondered what that sticky layer of frosted crystals on your cannabis actually is? Sparkly and aromatic, the sugary crystals that cover the buds are called trichomes. These little mushroom-looking glands produce the resin that covers cannabis buds that earned it the moniker ‘sticky icky’.

These microscopic glands are part of the plant’s defence and reproductive system, they are the site where pre-phytocannabinoids such as THCA and CBDA are created and stored. Prized for their contents, trichomes are an essential part of the cannabis plant: here’s our guide to what they are and what they do.

What are Trichomes?

Trichomes are protruding growths that appear in the flowering stage of the plant’s life cycle. They cover the leaves and flowers with a layer of resin which acts as a self-defence mechanism that is also critical for reproduction. In nature and when cultivators are pheno-typing the sticky little growths catch pollen from male plants in order to produce seeds, which is why trichome production intensifies the closer the plant gets to harvest. They're trying to reproduce. As the reproductive areas of the plant are the most important for its survival, the buds are densely covered in trichomes, this is where they play a role in self-defence. The production of terpenes and cannabinoids within the trichomes create a bitter taste and strong aroma, making them undesirable to animals and insects.

Trichomes function by transporting vacuoles and plastids from the stalk into the gland head, where they are metabolized to form precursors that will eventually become cannabinoids.

Trichomes are incredibly delicate, note the area where the flower was likely touched, creating sticky stringers from the gland heads.

This is where it gets a bit technical. Trichomes come in various shapes and sizes— the non-glandular trichomes are called cystoliths and are not thought to produce phytocannabinoids. Glandular types appear as bulbous trichomes, which are the smallest ones, 10-15 micrometres, around the size of a couple of cells and they appear all over the cannabis plant.

Capitate sessile trichomes are a little larger, with a mushroom-like head and a stalk, and are commonly found on the underside of the sugar and fan leaves.

Capitate-stalked trichomes are the largest type and they can be seen with the naked eye. These are the frost on your cannabis flowers. These trichomes range between 50-100 micrometres wide and have a more complicated structure, which includes a stalk, made of epidermal and hypodermic cells, that builds up to a basal cell and a large gland head. A waxy cuticle layer holds together the gland head, which is where phytocannabinoids, terpenoids and flavonoids are biosynthesized.

What do Trichomes do?

Trichomes are little factories pumping out all the good stuff we want to preserve and consume. Trichomes biosynthesize phytocannabinoids, terpenoids, and flavonoids, including THCA and CBDA, which become THC and CBD after decarboxylation (heating). When we consume the trichome-covered buds, it’s the cannabinoids that produce the desired effects while the terpenoids, and flavonoids provide the taste profiles and aroma.

What Affects Trichome Production?

Licensed Producers keep an eye on the trichomes as they grow and change colour at various points in the plant’s life cycle. At the beginning of the flowering phase, they start off clear and translucent, before turning to a milky, cloudy, opaque colour as they get ready to reproduce. This is the point that buds are usually harvested. If plants are left to mature, the trichomes begin to turn amber when THCA starts to oxidize into CBNA, the precursor for cannabinol (CBN), which is a cannabinoid thought to have a sedative effect.

Genetics and environmental factors affect the production and abundance of trichomes. It’s not necessarily true that plants containing higher concentrations of trichomes will always produce the highest concentrations of cannabinoids, but other factors such as UV light are known to increase the biosynthesis within the trichome head.

Trichomes are fragile and easily damaged, so factors such as harvesting, trimming, and curing methods are very important. Physical contact, heat, light, oxygen, and time all negatively affect the quality of the trichomes and can cause oxidation, which is why it’s recommended to handle with care and store cannabis in a cool, dry, and dark space.

A dried flower that was harvested at the right time will look like it's been dusted with frost.

Cannabis is a dynamic plant that only gets more intricate the closer you look. It starts with a healthy plant, which will then produce healthy flowers covered in the most critical part of the end product, the trichomes. They create and contain the cannabinoids and terpenes that interact with our bodies to produce the psychoactive experience and aromas that make the flower so appealing.