There are many different methods to use when determining the perfect time to harvest your cannabis plants. While some growers determine their harvest date by counting how many weeks have passed since they first planted, others harvest purely on the color of their pistils and trichomes. It's important to realize that every strain and every plant is different, so results may vary. 

The Anatomy of The Cannabis Plant

There are male and female cannabis plants. The males help produce seeds and pollinate the female plants, and the females produce the cannabinoid-rich buds, such as Delta-tetrahydrocannabinol (THC) and Cannabidiol (CBD). If you're trying to decide when you should harvest your nugs, you need to know and look at a few parts of the female plant.

The female cannabis plant has several parts, five of which are the most important:

The Cola — This is the part of the cannabis plant that we see as buds. They are clusters of cannabis that grow tightly together. These clusters remain at the top of the stem of the cannabis plant.

The Calyx — This is the organic tear-shaped flower or bud of the cannabis plant. It’s within the calyx that we find the good stuff - such as the highest concentration of trichomes and cannabinoids.

The Pistil — This part of the plant is most commonly known as ‘tiny hairs’. Pistils are found on the flower or bud of the cannabis plant and vary in color depending on the strain and maturity of the plant. Pistils are the female’s reproductive organs that pick up pollen from the male cannabis, which helps her to fertilize and produce flowers. These tiny hairs start out white, then as they mature they change in color from yellow, orange, and finally brown.

Trichomes — These are mushroom-shaped crystal resins that coat the cannabis plant. They contain terpenes and cannabinoids which determine the potency of cannabis plants.

Leaves and Stems — This part of the plant contains very low amounts of THC. For the most part, the stems are used in extracts such as tinctures. As for the leaves, they are typically thrown away and not needed.

The Problem With Counting Weeks

For those just starting out, harvesting cannabis takes time, patience, and a keen eye. As mentioned before, some growers count the weeks since they first planted. Depending on the breed and strain of your cannabis, counting the weeks will vary, as there are several variations to take into account:

• The amount of light your cannabis is exposed to.
• The amount of water your cannabis receives.
• The amount of nutrition your cannabis receives. 
• What type of cannabis you're growing (indica, sativa, hybrid.) 

Although it’s important to have an estimation of the flowering cycle and the flora of your cannabis plants, these are just estimates. Even if your cannabis plants come from the same parents, not all will grow and mature the same way.

There’s a certain phenotype, or a certain group of traits, that each plant expresses: growth pattern, vegetative energy, bud and resin production, etc. Some breeds and strains mature later than others; this is why counting the weeks may not be as effective in achieving the best results in your harvest. However, there is a more effective way to know when to harvest your cannabis plants.

Harvest Based on the Pistils and Trichomes

When it comes to harvesting cannabis, timing is everything, and if there’s one thing to take away from this article it’s that all plants are different. While certain cannabis strains can flower in 6 weeks, others can take up to 10 weeks to flower, so observing each individual plant works best. You should already have an idea of how long the flowering cycles are for your specific strain on average.

If not, you need to stop here, look up your specific strain's info, and then come back to this article. Once you have a general idea of how long your strain's flowering cycle is (and once you start nearing the end of that cycle), you need to observe the characteristics of each individual plant to determine when it's time to harvest. 

Pistils

The pistils are the tiny hairs you see on your cannabis plant. They are visible to the naked eye. When your cannabis is nearing harvest time, the pistils will curl and start to change in color, from white to yellow, orange, and finally brown. In some strains, the pistils will change color by the time you harvest, while others will stay completely white even if they’re ready to be cut.

To develop a more psychoactive crop, it’s best to harvest your cannabis when you see more than 50% of the pistils brown, while the other half are either white or are at the beginning phases of changing. Again, you'll have to look up specific details for your individual strain.

As the flowers of your cannabis plant mature, some leaves may begin to wilt or change in color. This process is completely normal for your cannabis. Some growers prefer to trim these leaves off, which allows more light to reach the other parts of the plant.

Trichomes

As your cannabis plant matures, you will notice tiny little crystals that make up a sticky coating on the buds of your cannabis plant. These are called trichomes. These crystal-like substances are responsible for the color and aroma of your cannabis plant, as well as the potency of the cannabinoids they contain. If the trichomes are still clear, it’s a sign that your plants are not ready. If they’re milky, that’s a sign that your plants are currently at their highest levels of THC.

Finally, as trichomes start to turn amber or brown, this is a sign that your plant’s THC levels are decreasing and CBD levels are increasing. Unfortunately, these trichomes are incredibly small which makes it difficult to see them with the naked eye. However, there is a handy tool to use that can help you better view the trichomes.

The jeweler’s loupe, a small magnifying device, is designed to spot imperfections in diamonds and other small pieces of jewelry. Most offer 30x magnification and others even greater amounts. It’s best to get one that offers two lens strengths, preferably no less than 30x lens each. These well-built tools are generally affordable, and some even come with two assisting lights which make viewing much easier.

Learning when you should harvest your cannabis plants can be tricky and overwhelming at first. Cannabis is a complex plant and varies in many ways. Taking note of your cannabis growth patterns, vegetation, and production is a huge part of what makes a good crop. However, lighting, watering, temperature, nutrition, and other factors also play a huge role in developing top-of-the-line cannabis. Research is key. And remember, patience and observation are the main ingredients needed in determining when your cannabis plants are ready to be harvested.