What are trichomes?
Trichomes are tiny glands, shaped like little hairs with a ball on the tip, that cover the buds and the small surrounding leaves of the cannabis plant. They are where almost all the THC, the other cannabinoids and the terpenes are made and stored.
If you look at a bud up close, you'll see that it looks covered in frost or sugar. That sparkle is thousands of trichomes packed together. They are so small that you need a magnifying glass to see them properly.
The little ball on the tip is a kind of storage tank: that is where the resin builds up, that sticky substance that stays on your fingers when you touch a flowering plant. So when a grower talks about a "very resinous" plant, they mean it has lots of trichomes.
Trichomes aren't unique to cannabis. Many plants have them: the little hairs on tomato leaves, which leave that distinctive smell on your hands, are trichomes too.
What does the plant use them for?
They are thought to be a form of defense: the sticky resin and its strong smell make it harder for some insects to attack and protect the flower. For growers, they are the most valuable part of the plant, because they concentrate the aroma and potency.
Trichomes and the right time to harvest
Many growers look at the trichomes under a magnifying glass to decide when to harvest. As the plant ripens, the little ball gradually changes in appearance:
- Clear: the plant isn't ripe yet.
- Milky or cloudy: the plant is reaching its peak.
- Amber: some of the trichomes are already past their peak.
There's no exact proportion that works for every strain. That's why it's a good idea to combine what you see in the trichomes with the flowering time the seed bank gives on the product page.
Handle the plant with care
Trichomes are fragile: they break and fall off when rubbed. The less you touch the buds during harvesting, drying and curing, the more aroma they will keep.
Related terms
Before you grow, check the laws in your country: growing cannabis is not allowed everywhere.
