When it comes to cannabis, the trichomes are the most important part of the plant. They contain all cannabinoids and terpenes so they are responsible for the taste, aroma and effect of your cannabis. Without them, cannabis would be “useless”. The best way to judge the maturity of the plants is by examining the resign glands, also called trichomes. Using a microscope with ideally a 100x magnification, you can easily determine the state of the resin glands and take the guesswork out of the equation.
When you purchase cannabis seeds, you usually have information about flowering times, but you must keep in mind that times are guidance only.
So the best thing you can do is abide with the trichomes.
Clear trichomes only contain precursor cannabinoids and those are not psychoactive. Harvesting at this stage will not give you a potent product.
We call these fresh trichomes “empty”. This means that they don’t contain any cannabinoids, terpenes or flavonoids. However they quickly start to fill up with these compounds, so this moment of them being “empty”is very short. The transparancy will stay for a while, even when there are cannabinoids present.
Milky resin glands contain fully matured THC. To obtain the most potent buds you want to get as close to 100% cloudy trichomes. Note that it is impossible to get 100% cloudy trichomes, since new resin glands are continuously being produced. Also, even after you harvest the trichomes will continue to develop.
After a while, your calyxes, buds and “sugar-leafs” will be covored in trichomes. This is the moment they start to fill themself up with multiple cannabinoids and terpenes. at the beginning, it’s mostly THC that will fill and colour the trichomes (combined with some other cannabinoids). THC will give the trichome a bright white colour. So you will slowly see a transition from transparant to white. This process could also take up to a few weeks and not all trichomes will colour at the same time. With a magnifying glass this will be clearly visible.
Next to cannabinoids like THC, there are also terpenes that will start to evolve inside the trichome. These terpenes will take care of the smell and taste of the cannabis. Different terpene profiles will offer different odors. In this phase, your growroom will start to smell strongly!
The most important aspect is that THC will slowly turn into CBN. The longer you wait, the more this happens. This means that the cannabis will turn more physically after consuming and giving you a numb/heavy feeling in your body. Good for sleeping and relaxing.
This will actually be visible in the trichomes! When this happens, you will see the white slowly turning into an amber/brownish colour. The trick is to find the right balance based on your own wishes. Once 20-30% of white trichomes have turned into amber, it’s time to harvest!
You can control the effect of your bud by harvesting a little earlier or later. By harvesting early you will obtain a product that provides a more cerebral inebriation („high“), whereas harvesting late will give you buds that trigger a more body-centered effect („stoned”). Thus you are able to obtain buds that will provide the kind of effect that best fits your needs.