When to Harvest Cannabis— A Complete Guide

Growing your own cannabis at home is a great way to learn more about the plant, the ways you like to consume it, and how it works best for you. This process is a rewarding labor of love and filled with plenty of opportunity for trial and error – especially when it comes to harvest time.

“The harvesting period, followed by the drying and curing stage, is so crucial and unfortunately, is where a lot of mistakes are made,” said Evan Marder, Cannabis Community College Professor of Cultivation for the “Cultivation Essentials” course and the President of Fleur Brands. “This is where good work can be ruined, so the utmost care needs to be taken throughout.”

Knowing when to harvest cannabis plants will vary greatly depending on several factors, like whether you’re marijuana harvesting indoors versus outdoors, the climate you’re harvesting in, the type of plants you’re working with, and more. This article outlines some of the most important things to know about harvesting cannabis before you embark on your homegrown journey.

Cannabis growth stages

The plant goes through four distinct growth stages during cannabis harvest: germination, seedling, vegetative, and flowering.

Different factors will determine the length and duration of each stage, like various cannabis strains, terpene content, cannabinoid makeup, and more, but each plant will be generally similar to the next as long as you pay close attention to its individual needs and make sure to meet them.

Germination, which takes place within the plant’s first 3-10 days, all starts with the seed. Once your seed has germinated (if it’s dark brown it’s ready, if it’s green or milky white, it’s not there yet), it’s time to move it to a growing medium, like soil, to begin the process.

That brings you to the seedling stage, which will last about 2-3 weeks. In this stage, your plant will begin to sprout little baby fan leaves with vibrant green color. This is one of the most vulnerable stages your plant will endure, so you’ll want to make sure your plant is clean, healthy, and receiving the right amounts of light and water.

Next is the vegetative stage, a 3 to 16-week period where your plants grow quickly. By this point, your plant will have been moved to a larger pot and will require a good amount of nutrients and water to continue thriving.

The final growth stage of the cannabis plant is the flowering stage, which will run for about 8-11 weeks. This stage is the most important and exciting, as you’ll begin to see your cannabis plant develop pistils, resin glands, and trichome color and density. 

As your plants get ready for harvest, the flowering stage can be broken up into three key subphases: flower initiation, when the plant continues to grow and develop the beginning buds; mid-flowering, where the plant will cease growing and the buds will begin to fatten; and late flowering, where trichome density will increase and the pistil color will tell you whether or not it’s time to harvest – pay close attention here because you definitely won’t want to run the risk of being early to harvest and damaging a good crop.

How to tell when it’s time to harvest cannabis

In a market increasingly concerned with terpene content, it’s important to be able to examine your marijuana plants throughout the four stages and ensure they’re doing what you want them to do. Then, it’s time to start your harvest period, keeping the full entourage of cannabinoids and terpenes at top of your mind. 

Depending on the type of grower you are and what your level of experience is, there are two common ways to determine whether or not it’s time for your growing cannabis plants to begin the harvest: with the naked eye or with a magnifying glass or digital microscope. 

More experienced growers are likely to utilize the naked eye, examining the cannabis flowers closely for pistil color. A mature plant ready to begin harvest will have pistils – a.k.a., the little pieces that look like scraggly tufts of hair – that have begun turning red or brown. 

The closer your plant is to maturation, more and more of its pistils will turn red or brown, and a good rule of thumb to refer to is the rule of 50: when about 50 percent of your plant’s pistils have turned, it’s time to begin the harvest.

For growers with the luxury of a magnifying glass or digital microscope, you’ll practice the same hunt for pistil coloration, while also being able to check the trichomes. When enlarged, trichomes resemble mushroom-like glands and contain most of your plant’s cannabinoids – a.k.a., the bread and butter of your crop.

You’ll approach the trichomes in a similar fashion as you did for the pistils, examining their color to determine how close your plant is to harvest time. Similar to pistils, trichome color will transition from a milky white or translucent shade to a shade of amber—amber trichomes signify that it’s time to harvest the potted plants.

For most plants – especially hybrids – a milky trichome color means your plant is experiencing peak THC levels, which is when most growers decide to begin the harvest process. Of course, this depends on the desired outcome you have for your plants and their THC content, so keep that in mind when paying attention to trichome color. 

A good way to think about it is light versus dark: when your trichomes are closer to translucent, the high you’ll experience will be more energetic and creative, while a darker amber color will result in a heavier, couchlock-like high.

Another great way to determine when to harvest is leaf color. Cannabis fan leaves will change shades throughout the growing stage, and when it’s time to harvest, the leaves will turn yellow and begin to fall off. The leaves may also curl and dry, signifying they’re taking in less moisture, which also means it’s time to begin the harvest.

Finally, pay close attention to the shape of the cannabis buds. The firmer and tighter your buds are, the closer your plant is to harvest time, where you’ll trim your plants down and get them ready for the final steps.
Once your plants have begun the harvest process, your next step to worry about will be the dry and cure process. This is the final stage before your cannabis flower is considered fully mature, thoroughly prepared, and ready to consume. It’s also your last chance as a grower to optimize flavor and effect by properly preserving terpenes and cannabinoids.

Drying cannabis best practices

Once the harvest period is over for your plants, it’s time to dry, trim, and cure. You’ll begin by drying your plants: a.k.a., hanging the individual branches upside down on a line or hanger to prevent them from getting misshapen throughout the process.

“You don’t want to dry too fast, you want a nice, slow dry of at least 10 days,” Marder said. “Check the moisture levels on the plant regularly to determine when it’s time to enter the curing phase.”

The dry versus trim order will depend entirely on your preference as a grower. While some prefer to dry and then trim the plants after, others opt for wet trimming, which will require you to trim your buds and then place them on a rack to dry.

Marder believes dry trimming is the best way to go, as it prevents trichome loss and depletion of chlorophyll.

“Wet trimming creates a nasty taste on the plant,” he explained. “Anything that’s wet-trimmed can’t be used in a CO2 extraction process either, which is problematic for many producers.”

Either way, this is a crucial step in the maturation process and must be approached with care. A good drying room will have the perfect balance of light, temperature, and humidity. A dark room with a temperature between 60-70 degrees Fahrenheit and 55-65 percent humidity is ideal. You may also want to utilize a small fan for air circulation, and a dehumidifier to keep the moisture levels consistent.

How to trim cannabis

Trimming marijuana sounds pretty self-explanatory, but you’ll want to be aware of a few necessary details before embarking on this piece of the puzzle. 

Trimming removes the buds from the plant itself, and will involve you cutting off branches, sugar, stems, and fan leaves – all of which are harsh on the smoking lungs and contain little to no trichome content.

This is important for aesthetic appeal: consumers love big, beautiful, cared-for buds, and whether you’re growing for friends, customers, or yourself, you’ll want your plants to be presented in a way that reflects all of the hard work and tender care you put into the growth process.

Curing cannabis

The final step in the cannabis growth process is curing, which is one of the most underrated aspects of cultivation.

Curing involves storing your flower in airtight containers such as mason jars or totes, halting the loss of moisture and preserving its flavor, aroma, and cannabinoid and terpene makeup. This period can take anywhere between two weeks and one month and requires a similar humidity level to that of the drying process (55-65 percent).

This is especially important if you’re planning to smoke your cannabis. Curing has a powerfully positive effect on your plant’s smokability, preserving the terpenes and allowing you to store your harvested weed for longer periods of time without having to worry about degradation or mold. Properly cured weed can last for up to two years without a significant or noticeable loss in potency.

Make sure to pack your buds loosely without compacting or crushing them before storing them in a cool, dry environment. If your buds look too dry, you can always toss in a humidity pack, and if they appear too wet, simply leave the lid off your airtight container for a day or two, checking the humidity levels throughout.