When to Harvest Cannabis Plants?

Harvesting cannabis is akin to a festival for beginners. After waiting for months together, they finally get to cut down their precious buds and use them. 

Of course, you'll have to dry and cure the buds to bring out their smooth flavors, but we will focus only on harvesting in this article. 

For most new growers, harvest is an exciting time (understandably), but what often confuses them is when to harvest. 

What if you cut too soon or too late?

Will it even make a difference?

Yes, the timing of harvest plays a significant role in the quality. 

In this article, we will delve into everything you need to know about harvesting cannabis plants. 

Average Time From Seedling Stage to Harvest

One thing that's confusing about cannabis is that different strains behave differently. And then, you have photoperiod vs. autoflowers that can be even more confusing for beginners, especially when it comes to harvesting the buds. 

In addition, the duration required to grow depends on many factors like the growing medium, training methods, strain genetics, and desired yield.

If everything goes according to plan, the plants may take from six weeks to 16 weeks after germination. Why such a vast difference? As mentioned, it depends on the type of plant you grow. Although, on average, most cannabis plants are ready to harvest from 9 to 12 weeks indoors. Growing outdoors will take a lot more time. 

So, the first thing you must do to figure out the best harvest time is to understand the strain genetics and your local growing conditions. You can even talk to growers in your local region and see what kind of growth period their plants (of similar genetics) are experiencing. 

The Best Time for Harvest

Understanding your local weather and strain genetics will give you a general idea of when your plant will be ready to harvest. Now you need to narrow it down. 

We have broken this section into two parts — first, knowing the harvest time based on the grow location (indoor or outdoor), and second, looking for cues that show your plant is ready.

Grow Location 

Cannabis plants are grown either indoors or outdoors. Here's how to know when your plant is ready based on where you are cultivating, indoors or outdoors.

Cannabis is a warm-season plant, so you need to plan accordingly. For instance, it should be ready for harvest between September and November (in the northern hemisphere) if you are growing outdoors. But, of course, there might still be some variations depending on your local climate.

On the other hand, if you are growing cannabis indoors, the harvest time depends on when you flip the plant into bloom by changing to a 12/12 light cycle. 

Also, remember that the harvest varies significantly depending on whether you choose a photoperiod or autoflowering strain. 

Visual Clues

The second way to figure out the harvest time is to look at the visual clues your plant exhibits. Here's what you must look for:

Trichomes Turning Milky

Trichomes, the small resin glands on the buds, are perhaps the most reliable way to know when your plant is ready for harvest. 

Use a magnifying glass to look at the trichomes — half of them should be milky or cloudy, and the others should be amber. This is a sign that your plant is ready for harvest. That said, it's impossible to look at all the trichomes to determine the color. Therefore, just do your best, and you should be okay. Moreover, you'll get the hang of it with experience, so take your time. 

However, if you see too many clear trichomes, it's perhaps a tad too early. Just wait a bit to harvest the buds. 

Use a 30x to 100x magnifying glass that you can find at your local supply store to look at the trichomes.

Pistils Turning Orange and Curling

Pistils are white hairy structures found on female cannabis plants. They are usually straight when the plant is still in the early stages of flowering. However, as time goes by, you'll notice they begin curling, which indicates that the plant is almost ready to be harvested. In the image above, you can see that some pistils are white whereas some have begun to turn orange and are curling up. 

The originally white pistils will change their color to orange or amber gradually. Sometimes, they even appear red. And, this happens in all cannabis plants including autoflowers and photoperiods. 

Note that the pistil method may not be as accurate as the trichome method, so it's best to get your hands on some magnifying glasses. 

Leaves Turning Yellow

During the flowering stage, your plant uses a lot of nitrogen, which gives the leaves a vibrant green color. When the bloom stage ends, the plant no longer uses much nitrogen, and the fan leaves turn yellowish. This is a good indicator that you can harvest your plant. Of course, the leaves can also turn yellow if there's a deficiency or a pH imbalance, but it usually indicates that the plant is getting ready to be cut down if it occurs at the very end of the flowering stage. 

Leaves Curling Up

Similarly, your plant also decreases its water consumption after the flowering stage. Due to this lack of moisture, the leaves start curling up and drying. Once this starts happening, you can harvest your plant.

Do note that curling leaves can also signify nutrient deficiency or under-watering. Always use this sign with other signs to ensure your plant is harvest-ready and not suffering from stress.

Pistils Turning Brown

Lastly, if you notice half of the pistils are turning brown, you can start prepping up for harvest. Brown pistils are a sign of the plant's maturity. Again, use your magnifying glass ready because pistils are tiny.

Look for these signs to know if you can finally harvest your plant. 

In some plants, especially tall ones, the top-tier buds may ripen faster than lower ones because the latter doesn't get enough light. Thus, it's best to head over to the seed manufacturer's website to know what to expect. 

Or, talk to other growers here at Growdairies to get a rough picture.

The Wrong Time to Harvest

Like the visual clues mentioned above, your cannabis plant will show various other signs that indicate if it's the wrong time to harvest it. 

If most trichomes appear clear — not milky or amber — then your plant is still not ready for harvest. Also, the buds won't be as flavorful, aromatic, and potent if you harvest at this point.

On the other hand, if most of the trichomes on your plant are amber or brittle to touch, then the buds are overripe. These overripe buds tend to have a slightly bitter taste.

So, we recommend you err on the side of caution and harvest the plant when 50% of the trichomes have turned white. On the other hand, don't wait too long either — harvesting the plant when fully mature is not recommended because the buds won't be flavorful or aromatic — think of it just like harvesting any other vegetable. You need to pick them at the right time for maximum benefits. 

Tips for Knowing the Harvest Time for Outdoor Plants

You have complete control over your plant's flowering cycle in an indoor environment, but you have less control when growing outdoors. So, here are some tips on when you can expect your plant to be ready.

Know Your Strain

As mentioned above, strain genetics dictate the harvest time for most cannabis plants. For example, some users report that indicas are faster than sativas, but there's no concrete evidence. Also, it depends on whether you're growing a photoperiod or autoflowering strain. 

Follow the Weather

Once the season changes from summer to fall, your plant's buds will start putting on some weight. However, if you suspect the weather to fluctuate drastically during this period, make a quick decision and harvest the plant. Bad weather can damage your plant quickly. 

If the temperatures are expected to drop, you need to harvest quickly. Your plant can survive a light freeze (from 28°F to 32°F or -2.222°C to 0°C ), but that's only for a few hours. 

Ice crystals can form on the plant's tissues during such cold spells, which damages the cells, making the leaves wilt and turn dark and crispy.

Also, outdoor plants growing in pots are more prone to frost damage than ground-grown plants because the ground provides better cold insulation to the roots.

Similarly, you need to harvest the plant if you expect a lot of rain. Little rain isn't a problem, but prolonged or heavy rainfall can cause mold infestation on your buds. So, it's better to harvest your plant beforehand than potentially lose all your yield.

Harvest Frequency

If you want a continuous supply of fresh buds to smoke up, you can even harvest your plant a couple of times a year — but this depends on various factors. So let's take a look at them.

Indoor Plants

If you are growing your plant indoors, you can harvest them as many times as you want. Of course, it's easier if you have two tents. Or, grow autoflowers. Since indoor plants are easier to control, you can plan and set them up for a perpetual harvest. 

Generally, indoor plants become harvest-ready in 3 to 8 months, so you can fit two to four harvests per year depending on the plants' size, strain, and more if you grow autoflowers or clone cannabis.

Outdoor Plants

Outdoor photoperiod plants can be harvested only once a year during the fall season, except for those growing in tropical or similar climates, where you can harvest them twice a year.

On the other hand, outdoor autoflowering plants can be harvested a couple of times a year since they have a shorter life cycle. So, if you are growing autoflower cannabis, you can develop the first batch in March and harvest it in June or July and start another batch in Fall. 

Summary: When to Harvest Cannabis?

Harvesting is an exciting time, but knowing the right time is crucial. So, take your time to figure out when your plant will be ready and follow the recommended advice to harvest it. 

Remember, there is no right or wrong when it comes to harvesting — every grower has a different preference. And, you can use your preferences to your advantage, too:

• If you are looking for a head high, harvest the plant early when only 40% of the pistils have turned dark and more than 50% of trichomes have turned milky. 
• Wait until all the trichomes are milky but not amber for the highest potency.
• For a relaxing high, harvest when some trichomes have turned amber.

And don't worry if you are off by a week or so. It won't significantly affect your plant. But don't harvest the plant too early or late — the buds won't be as good as you expect.