Harvesting cannabis plants at the optimal time ensures the highest quality buds and potency.

up close shot of man trimming cannabis flower with surgical scissors

With restrictive laws governing cannabis consumption and cultivation loosening across the country, there are many novice cultivators playing farmer for the first time. If you are one of the newbies wondering if now is the optimal time to harvest your cannabis, put the gardening shears down and take a deep breath. The last thing you want to do is improvise in the field and risk losing your precious bounty to beginner’s bad luck. 

In this article, we’ll walk you through everything you need to know about the end of your beloved pot plant’s life cycle—the harvesting signals you need to look for, the tools you’ll need on hand, and the basic anatomy of the cannabis cultivar. 

Cannabis Plant Anatomy

It’s important to know what you’re growing before you begin producing it. With that in mind, this section deconstructs the cannabis plant to demonstrate what you’re looking at and how it factors into your final product. 

Cannabis consists of the same basic anatomy of all plants: a seed that produces roots on the bottom and a stem on the top, with the stem growing from the soil and eventually producing leaves, branches, and flowers. Of course, the magic of THC separates the cannabis plant from other shrubs and flowers. Let’s check out the basic anatomy, define the terminology, and examine each segment’s role at harvest time.

Stem

The stem keeps the plant upright, supporting its weight while housing the vascular system that ferries nutrients and moisture from roots to leaves. The stem also carries starches and sugars created during photosynthesis around the plant or into storage via the phloem cells, which can be harvested for hemp fibers. The stem contains little to no cannabinoids (THC and CBD).

Fan Leaves

The gloriously iconic fan leaf has become the universal symbol for marijuana. Shaped like an open hand with multiple parts and separated into three to 13 serrated leaflets, the leaves are removed at harvest. Fan leaves contain only trace amounts of cannabinoids. 

Petioles

This is the stem of the fan leaf, connecting it to the larger branch. Petioles contain more cannabinoids than fan leaves, making them a useful additive for tinctures, extracts, and concentrates when gathered in large quantities.

Stigma and Pistil

As in the anatomy of many plants, the pistil houses the cannabis flower’s reproductive organs, and the stigmas are the vibrant strands found on the pistil. Stigmas collect pollen from the male cannabis plants and change color throughout the maturation process, beginning with a white haze and eventually darkening to yellow, orange, brown, and red. While crucial to the growing process, stigmas and pistils have little impact on potency. 

Bract and Calyx

The female cannabis plant’s reproductive parts reside inside the bracts, which are green, tear-shaped leaves. The bract is covered in resin glands that produce higher concentrations of cannabinoids than any other part of the cannabis plant. Tucked inside the bract and hidden from view is the calyx, a translucent layer covering the ovule on the flower’s base. 

Trichomes

This is where all the action happens. Tiny, hair-like structures located on the surface of the buds, stalks, stems, and leaves of the cannabis plant, trichomes form a blanket of frosty, crystal resin that oozes the aromatic oils called terpenes, as well as the all-important THC and CBD cannabinoids. Though their practical purpose involves protecting the plant against microbial organisms, aphids, and insects, everything you work for in the field hinges on trichomes and their potent, sugar-like resin. 

Cola

This refers to the cluster of buds that grow tightly together. The primary cola forms at the very top of the cannabis plant and is sometimes called the “apical bud.” However, many smaller colas will likely be found on the budding sites of the lower branches. 

Female vs. Male Cannabis Plants

A quick note: Cannabis plants are dioecious, meaning they can be male or female. The buds that make up your personal stash are the flowers from the female plant. Only the female cannabis plant produces the resin-secreting flowers that deliver the high we want. 

When Is The Right Time To Harvest Cannabis

This is it! It’s the beginning of the end for your beloved pot plant’s life cycle. You’ve watched your cannabis survive all of the peaks and valleys of cultivation, and it’s finally the optimal time to harvest your precious bounty. However, now is not the time for rash decisions and improvisation! Here, you’ll learn pro tips for the right time to harvest, how to do it, and the tools of the trade you’ll need to get the job done right. 

There are two basic methods to determining if you’ve reached peak harvest time: The pistil method or the trichome method

The Pistil Method.

As a pot plant approaches maturity from the vegetative stage to the flowering stage, the pistils will stick straight out from the flower’s body in a pure, white coloring. You’ll know your plant is ready to harvest when you witness with the naked eye at least half the pistils change to a darker hue and curl back toward the flower. 

The Trichome Method.

For this method, you’ll need either a jeweler’s loupe, a magnifying glass, a digital microscope, or even the camera on your smartphone (which can be incredibly high-powered these days). If the trichomes resemble clear, glass-like mushrooms, you’ll know it’s not quite time to harvest. But when at least 50 percent of the trichomes turn cloudy, it’s finally time to reap what you’ve sowed.

As for a timespan of when to harvest, that depends on the cannabis strain. Different strains boast varying flowering and harvest times. As a general rule of thumb, indicas are ready for harvesting at about eight weeks, while sativas hit harvest time at ten weeks. Meanwhile, autoflowers can take anywhere between seven to 10 weeks. 

What do trichomes look like when ready to harvest? Other signs to look for at harvest time include dense soil and leaves that have turned yellow and crisp. When the soil is dense, it means your plant isn’t consuming as much water as usual. And when the leaves begin to yellow and become crispy, it means the plant is ripening and could be ready for harvest. But before you pull any buds, make sure to check the trichomes and pistils in conjunction with checking the soil and leaves.

When to Harvest Cannabis for Maximum Potency

The best time to harvest cannabis is the moment when it has reached the greatest potency it will achieve. In addition to the methods listed above, it’s also possible to determine when cannabis is ready to harvest based on its cannabinoid potency.

This method is simple: Remove a few small nugs from a growing plant as samples. Take one nug from the top, another from the middle, and the last from the bottom of the plant. Then, use a cannabis testing device to determine the potency of each sample. Calculate the average of the three readings to counter for natural variances between individual cannabis plants, and compare your readings to the listed maximum potency of the strain you took your samples from. If your cannabis has nearly reached the potency limit its genetics allow, the time to harvest has arrived.

How to Tell if Your Plant Is Ready for Harvest: Indoors vs. Outdoors

There are a few important differences between harvesting indoor cannabis and harvesting outdoor cannabis. With the proper equipment, determining the harvestability of any form of cannabis is just as easy, but conventional methods vary significantly between outdoor and indoor approaches to cannabis cultivation. Let’s take a closer look at when to harvest pot plants based on where you grew them:

When to harvest cannabis outdoors

In most climates, there is only one viable cannabis cultivation season. Cannabis grown in the Northern Hemisphere is generally planted in May, and it reaches full size by July. Then, the late summer and early autumn months are spent flowering, the period in which cannabis expresses its active compounds, cannabinoids and terpenes.

Due to the constraints of natural cycles, there is only one proper time to harvest outdoor cannabis: early to mid-October. This inherent restriction limits the volume of outdoor cannabis that can be produced per year.

When to harvest cannabis indoors

You can grow cannabis indoors during any time of the year. The ideal cultivation time for cannabis varies from strain to strain, but in most cases, the full indoor cannabis cultivation cycle takes around 10-14 weeks. The first four weeks are dedicated to vegetative growth, after which the cannabis plant gradually flowers, releasing cannabinoids and terpenes.

The best way to determine when to harvest a cannabis plant grown indoors is to use a potency testing tool. Otherwise, consult guidance for the particular strain you’re growing—some cannabis strains flower fully within just seven weeks, but others can take nine weeks or longer to reach maximum cannabinoid potency and terpene expression.

How To Harvest Cannabis

First things first: Dress comfortably in clothes you don’t mind getting dirty. Next, make a nice, long playlist or pick out a podcast. Any sort of non-visual stimulation will do. Finally, grab these crucial cannabis gardening tools:

  • Shears for trimming and pruning
  • Powder-free latex gloves
  • Clothesline
  • Hangtags or hangers

Once you’re organized, it’s go time. 

  1. Check for mold.

Mold can seriously harsh your harvest time. Throughout nature, mold grows in the presence of oxygen and humidity—and cannabis plants are no different. Cannabis mold typically appears in two forms: Botrytis cinerea (a.k.a. bud rot) and Aspergillus. Both should be avoided at all costs. To check for mold, look out for slime, gray or yellow fuzz, dark spots, cobweb-like substances, and a powdery appearance. Also, follow your nose. If your buds smell putrid, you might have a mold problem. 

We don’t recommend smoking moldy weed. Instead, try decarboxylating the bad batch to get rid of any mold. Then, you can turn that patch into concentrate. You can also get rid of moldy cannabis by simply recycling it and using it as compost to feed a healthier harvest. 

  1. Cut down the plant and trim the fan leaves.

Cut the entire plant at the stem or trim individual branches. Then, trim the fan leaves off your pot plant. Remember, too many leaves can give the final product a harsh quality. 

  1. Dry your buds.

The simplest method to dry your buds is to use that clothesline and hangtags or hangers. Then, clip or tie the buds upside down in an environment that’s steady at 70-degrees Fahrenheit and 50 percent humidity. 

  1. Remove buds from stems and place them into jars.

After about three to seven days, your buds should be dried entirely. Then, remove the flowers from the stems and pack them loosely in a mason jar with a secured lid. 

  1. Cure your buds.

Like aging a fine wine, curing your buds allows them to develop to their full potential until they are bursting with a colorful spectrum of flavors and aromas. To cure your buds, store the jars in a dark room at 70-degrees Fahrenheit and 60-65 percent humidity. 

Enjoy The Fruits Of Your Labor

Congratulations! It’s the end of a laborious yet satisfying process. What a long, strange trip it’s been. There’s only one thing to do now: Reward your hard work by pulling some buds out of storage and firing it up. After all, somebody has to test the potency of your product, right? So it might as well be you!

GemmaCert Lite is a game-changing solution for micro-cultivators, craft cannabis producers, and home cultivators alike; our streamlined tool lets you test like a pro. Explore our entry-level in-house cannabis testing solution.

Learn More About GemmaCert Lite

Harvesting Cannabis FAQ

As you learn the best methods for “picking” weed from the vine, you might come across a few common questions. Find the answers below:

1. Can I harvest the top half of my plant?

Pruning is an important part of the cannabis cultivation process, but it is generally not advisable to harvest only the top half of a cannabis plant while leaving the lower portion intact. Doing so can stress the bottom half of your plant as it tries to survive the bisection, reducing the potency of the buds you’re trying to leave rooted for an extra boost at the end of the cultivation cycle. If you grow cannabis correctly, every part of the plant should be ready to harvest at the same time.

2. When to harvest marijuana vs. cannabis?

Recently, with-it people everywhere have started referring to cannabis by its scientific name, ditching the pejorative moniker “marijuana.” But, it remains a fact that these two names refer to the exact same plant, so there’s no difference between the harvest methods for cannabis and the methods used for marijuana.

3. Is marijuana plant anatomy different from hemp?

No, the anatomy of marijuana and hemp plants is practically the same. In both cases, the female plants produce the flowers and seeds, and male plants are only useful for fiber production and breeding. Both hemp and marijuana flowers express cannabinoids, terpenes, and flavonoids, which together form the “full spectrum” of desirable cannabis compounds.

4. How much should I spend on cannabis harvesting tools?

Between your pot scissors, additional trimming tools, and the other materials you use to harvest your cannabis, you shouldn’t need to spend much more than $100 per pound. Knowing when to harvest cannabis can make all the difference, though, and the cost of cannabis testing devices varies.

5. How long to flower a cannabis plant after it has reached full size?

You should only start thinking about harvesting buds after your cannabis plant has been flowering for at least six weeks. On average, cannabis is mature after around eight weeks of flowering, but the duration to maturity varies from strain to strain.

6. What are the most important cannabis harvest tips?

When harvesting cannabis and getting harvested buds ready for use, adhere the same guidelines you follow when using power tools: Measure twice, cut once. In this case, though, “measure” should be replaced with “test.” The only way to be absolutely sure your cannabis is ready for harvest is to test its potency, so cover your bases in this regard before investing into your grow op in other ways.

7. How can I use the GemmaCert to find the optimal harvest time?

Using the GemmaCert cannabis analysis tool to determine the optimal time to harvest your cannabis is easy. Start testing your flowers two weeks after you begin the flowering phase, and sample three plants out of every 100. Select sample nugs from the top, middle, bottom areas of the plants you intend to test, and continue testing the same plants regularly throughout maturation.

GemmaCert cannabis testing devices provide accurate, consistent data on the potency of your sample nugs as your plants flower. Use the growth chart accessible in the GemmaCert Customer Portal to track the maturation of your plants. Time harvest to coincide with the moment your tested plants reach the peak cannabinoid potency indicated for their particular strains.

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