jason-crawford

Medically Reviewed by
Jason Crawford

Article Last Updated on January 10, 2023

First-time cannabis growers have a lot of questions when it comes to cannabis cultivation, one of the most common ones being: “how to tell if the buds are ready for harvesting.”

If you harvest cannabis before it’s ready, you may get a low THC cannabinoid profile, and if you harvest cannabis too late,  you may end up with a “sleep medicine” on your hands that produces a couchlock effect. In other words, timing is key. So how to know when to harvest marijuana?

Harvesting time may be stressful for newbie growers, which is why,  in this article, we’ll give you all the information you need on how to tell when the perfect harvest window for your cannabis plants opens.

In order to determine the best harvest time for your plants, you’ll need to get familiar with the exact flowering time of your specific cannabis strain. You’ll also need a magnification tool. Don’t worry if you don’t have a digital microscope to get uncomfortably close to your buds, as there are other ways to check if the fruits of your labor are ready to be harvested.

How to Know When to Harvest Cannabis?

To check if your plants are in peak harvest you could try the pistil method or the trichome method. The first method only requires the naked eye, while for the second you’ll need a magnifying device.

Different cannabis strains have different flowering and harvesting times. As a rule of thumb, Indicas are ready for harvesting at about 8 weeks, Sativas at 10 weeks, and autoflowers take between 7-10 weeks. After your marijuana plant has been in the flowering phase for a while, it may be time to harvest it in order to get the psychoactive effects you want. Here are the most important giveaway signs that help you figure out when to harvest weed.

The Soil Is Very Dense

If the soil is dense, it means that the plant is ready for harvesting which is why it’s not consuming as much water as usual. Check if your plant gives other signs of being ready for harvesting apart from the soil being dense.

The Leaves Begin to Turn Yellow and Crisp

Another way to check your plant’s ripeness is to take a look at the calyxes (where you’ll find the pistils and trichomes) and the bigger fan leaves. If the plant is ripe enough, the leaves will turn yellow and start curling upwards.

Why Is It Important for the Plant to Reach Peak Harvest?

Not only will the appropriate harvesting time help the tetrahydrocannabinol (THC) reach its peak levels, but it will also prevent THC from turning into cannabinol (CBN). THC degrades to CBD if it’s exposed to UV rays and oxygen for a longer period of time. Once it degrades, it won’t provide a psychoactive experience but instead, turn into a sedative “sleep aid.”

Moreover, harvesting at peak harvest is also important for terpenoid production. As you may already know, terpenes are responsible for the flavor and smell that cannabis provides, and giving the plant the appropriate amount of time to develop them is the key.

Check if It’s Harvest Time With the Pistil Method

The pistils are the primary piece of the female flower’s reproductive system, along with the stigmas. Stigmas, the long white hairs that start out white when the plant is in the early stage, are the telltale signs that reveal the harvest window to an experienced grower. 

As the cannabis plant reaches harvesting time, some of the white pistils begin to change their color to amber or yellow, turning brown at the end, when the plant is ready for harvesting. When the pistils eventually turn brown and begin to recede, it signals that it may be harvesting time. 

The following guidelines will help you check if your plant is ready to be harvested:

  • 0-50% brown pistils (this an early time to harvest since the marijuana isn’t anywhere near its maximum cannabinoid potency);
  • 50-70% brown pistils (although this isn’t peak THC level, you can still harvest for an instant and mellow high, with a light taste);
  • 70-90% brown pistils (this is the optimal harvest time since it will give you high-quality weed);
  • 90% and over brown pistils (this is past peak THC content and the THC slowly degrades to CBN).

Depending on the strain, some plants may get new pistils right as you’re getting ready to harvest and that may throw you off. If that happens, try the next method.

Harvest Cannabis With the Trichome Method

Trichomes, also called resin glands, are the “crystals” that accumulate on the buds and leaves of your marijuana plant. Checking your trichs to see if your plant is reaching harvest time is another good way of going about it, especially if the pistils method isn’t as successful as you’d hoped. So what do trichomes look like when ready to harvest?

As the plant reaches harvesting time, a lot of the trichomes will become amber. Peak harvesting time is considered to be when you have 60-70% milky trichomes, 15% amber trichomes, and 15% clear trichomes.

You won’t be able to check this with the naked eye, so it’s best to look at trichomes under a magnifier in order to harvest cannabis buds with the THC levels you desire. If you don’t have a regular microscope, you could use other magnification devices like a pocket microscope, a magnifying glass, or a jewelers loupe

Clear trichomes, the sign that the plant isn’t ready for harvesting, look like polished glass, while milky trichomes look like frosted glass. Milky trichomes indicate that the bud has the highest levels of THC and CBD and is ready for harvest. If left longer, milky trichomes will have an amber color which indicates they have less THC and produce a relaxing and anti-anxiety effect (i.e. have a higher CBD content).

What Happens If You Harvest Too Early?

Many beginner growers make the mistake of harvesting too early, usually due to impatience or fear of letting the buds ripen past their peak. Sure, waiting for your cannabis seeds to grow and then to mature before you harvest them can take a toll on your patience, but the rewards are definitely bigger if you wait just a couple of weeks more. 

While harvesting too early is not a crime, it’s not recommended for many reasons. First of all, your overall yield will suffer – you’ll get anywhere between 20-40% less than if you give the buds a couple more weeks to grow in size. Also, the last 2-3 weeks of the cannabis plant’s life cycle are crucial for the buds because that’s when the cannabinoids and terpenes fully develop. The flavor and aroma will be much better, plus the cannabinoid content will be higher.

Buds that are harvested too early tend to give a less flavorful and more cerebral high, but they may also cause more headaches and anxiety because the terpenes, which work together with the cannabinoids, are underdeveloped.

What Happens If You Harvest Too Late?

If you had to choose whether to err on the side of harvesting too early or too late, choose the latter. While harvesting too late produces buds with a higher CBN content due to the degradation of THC to oxygen and light, it’s usually a better choice because the high is more flavorful and relaxing, and the chances of experiencing side effects are generally lower.

Harvesting too late is not ideal if you don’t like an overly sedative high and prefer the euphoria that comes with a higher THC content. The buds that were left to ripen past their peak harvest time have a more pronounced flavor, indeed, but if left to ripen for too long, the flavor may go bad quickly. The buds may start to wither due to aging, and some may even start to self pollinate in order to survive.

Thankfully, it’s easier to tell if the buds are starting to overripen and do something about it right away – to salvage them than to harvest them too early and be unhappy with the result.

Final Thoughts on Harvesting Your Cannabis Plants Without Using a Microscope

Overall, the perfect harvesting time depends on your personal preference. If you harvest your cannabis flower earlier, when only some of the pistils have turned a darker color, you can get a fast and light high. If you harvest your weed at a time when the buds have the highest THC levels, meaning 70-90% of the pistils have changed color, you’ll get the strongest psychoactive effects. And if you’re after more relaxing, anti-anxiety buds, wait for at least some of the pistils to grow red hair and for the trichomes to turn amber or brown.

To improve the quality and smoothness of your cannabis plant, you may also want to try flushing your cannabis plants before harvesting. Flushing means only watering them with plain water and no nutrients for a while before you plan on harvesting. Flush them for a week or two before harvesting if you’re growing in soil or coco, and for a few days if you’re growing in hydro.

In the end, the most useful way to know if your marijuana plant is ready for harvesting is to educate yourself and learn to recognize the flower ripeness in order to get high-quality buds. Happy harvesting!

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.

Disclaimer

The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.