Trichomes are single or multi-cellular outgrowths of the epidermis of a plant that form hairs over the plant’s surface. These epidermal hairs are in many types of plant specialised in defence against attack by insects and mites. The way in which trichomes are used for defence is determined by their density, length, shape and whether they stand upright or penetrate in to the leaf surface. The hairs form a physical barrier between the plant surface and the attacker.
In cannabis the trichomes excrete a resin that on the one hand serve to protect the plant against pests, but which also protects the plant against drying out, excessive UV-b rays, moulds and heat. The chemical substances we enjoy are produced within these trichomes, along the upper surface of the flowers (calyxes), leaf shoots, leaves and stems, beginning in or around the fourth week of the flowering cycle. More and more of these trichomes develop as the plant ripens. At the same time more and more flowers (also known as calyxes) develop and arrange themselves into tightly packed flower clusters.
The pistils of the young flowers are clear white and turn re-brown with age. The pistils and flowers develop from the underneath to the upper side of the buds. The older, lower pistils are the first to turn re-brown. For the most basic Indicas this usually happens around the sixth week of the bloom cycle. It’s around this time that the calyxes begin to swell.
Towards the end of the eighth week the majority of the calyxes have swollen and a strong increase in trichome development coats most of the buds. Patience is a virtue - and often a discipline.
Again, time and experience are the most important elements in this regard.
As the plant ripens its chemistry changes. Towards the end of the bloom desirable compounds will increasingly break down into less desirable ones. For a start there is a break down of THC in to CBNs and CBDs. The window of peak ripeness is when the trichome development and the level of THC production in your plant have reached their maximum point, this is the time frame in which we want to harvest. By being patient, you can harves fantastic buds that will give you exactly the kind of high you’re after. Which specific combination of chemical substances is most desirable to you is a matter of taste and choice, developed over time with experience.
Cannabis produces THC and CBN in its roots, stems, leaves, and in the vegetation that surround the buds. They are manufactured in the trichomes, which are found on the surface of most areas of the plant. In the stems and the earlier ventilator leaves, trichomes are small and stay close to the surface. As the flowering phase continues, the glands develop on the riper parts of the plant, including the small leaves and the first calyxes (which exist for the development of seeds and to nurture them once the male pollen has fertilized the female plant). These can be observed, looking like long stemmed mushrooms with ball-shaped caps on their tips.
Another indication of a plant’s ripeness is the colour of the pistils, the small hairs that grow from inside the calyxes. Their job is to collect up the male pollen for fertilizing the female ovum inside the calyx, creating a seed. When no male pollen is present the calyxes grow shut without a seed in them, resulting in sinsemilla (“seedless”) cannabis. Right at the end of the flowering phase the pistils change colour, signalling the ripeness of the plants. The change in the pistil is from clear white in to a rusty orange or brown colour, announcing the end of the lifecycle of the plants.
The majority of noob growers start plucking their plants barely a couple of weeks after the effloresence begins. Usually this is simply because inexperienced growers tend to get overexcited at their appearance and don’t appreciate that these little, unripe buds still have a way to go before they reach their peak ripeness and their highest level of trichome development.