Know When to Harvest Cannabis to Maximize Yield and Effects

Knowing when to harvest cannabis buds is important for the taste, smell, and potency of your weed. Once the harvest window kicks in and the plants are ready, you can wait as long as you need based on the effects you desire.

If you harvest the buds too early, you miss on the potency of your marijuana. And if you wait for late harvesting, you lose most of the THC as the plant converts that to CBN (Cannabinol).

Unless you need the sleeping effects of CBN, you shouldn’t wait for too long before harvesting your plants. If you need the highest potency, wait until the plant has the highest THC content and then chop it down.

What’s the Average Time from Planting Weed to Harvest?

Novice weed growers harvest too early. Other farmers might wait for too long and end up losing the THC. While a longer flowering period might mean a greater harvest, leaving your plants to flower for many months is not always the right choice.

If the plant takes too long after flowering, you could end up with an unpleasant flavor.

The best way to ensure that you do not lose out on the THC and flavor of your THC is to observe the flowering cycle of the plant.

When buying your seeds, you can see the typical flowering time on the seed packet. You will still need to observe the plants to know when they start to flower, but the seed manufacturer’s flowering time can help you.

Most of the marijuana strains will flower at the same time with only minor variations. To understand the flowering time better:

  • • Read comments on cannabis forums and see what other growers say
  • • Keep records of each growing cycle
  • • Read strain descriptions from the seed manufacturer

There are so many variables that affect how long a plant takes from planting to harvesting. The duration the seed manufacturer indicates on the description is for ideal growing conditions.

When the weather in your area doesn’t match what the seed manufacturer intended for the seeds, they might not flower as suggested.

As a rule of thumb, there is no accurate estimation of the harvesting time from planting time. You need to be keen and observe the pistils and the trichomes. However, the estimated flowering time is as follows:

harvesting marijuana indoors
Hand holding marijuana leaf ( Cannabis sativa indica )

Indoor Marijuana Plants

Indoor weed takes about 3-5 months. The first seven days are for the germination of the seed. Within the first eight weeks, the plant develops the leaves and becomes vegetative. At this point, you need to ensure the plant gets full exposure to light. Water the plants when the topsoil dries until the plant is about half of the desired size.

Indoor plants flower for about eight to ten weeks. You can initiate the flowering by use of glow lights, which come on for 12 hours and off for 12 hours. The plant will grow double its size during the flowering stage. You need to provide bloom nutrients for the best yields. The total flowering time will depend on the strain you plant.

The weed is ready to harvest when the pistils darken. It takes about a week to dry the chopped weed in a cool dark place. Once the week stems can snap, the weed is ready.

In summary, weed takes between eight weeks and seven months from the time of planting to harvesting – with the average being three-five months. The range is wide, but so are the factors that affect the duration it takes to grow marijuana. These factors include:

  • The strain
  • The environment
  • Your setup
  • Size of mature plants, taller plants take longer to grow
outdoor grow calendar e book

Outdoor Marijuana plants

When grown outdoors, weed takes longer between planting and harvesting. Here, you do not have control of the environment in which the plant grows. Changes in rain patterns, length of days, and so many other factors affect how long it takes your plants. However, the yield per plant might be more outdoors if you take care of your plant as you should.

It takes between five and ten days for seeds to germinate outdoors. Within the first six weeks, the plant will be at the seedling stage. The vegetative stage takes between three and 16 weeks.

You can provide the necessary nutrients and water the plants as needed at this stage. The flowering stage takes between six and 12 weeks within which the plant is ready for harvesting.

The outdoor plant will be ready for harvesting in between three and eight months. The growing method you choose, the seeds, and the strain of cannabis will determine the lifecycle of the plant.

Autoflowers and feminized seeds are different as they grow independent of the light cycles. In most cases, these seeds enter the flowering stage in two to four weeks. The flowering stage takes as little as six weeks and the plants are ready to harvest.

How to Know When Cannabis Is Ready to Harvest

Understanding the growth cycles of different strains will help you estimate when the plants are ready for harvesting. If the strain you grow takes four months indoors and six months outdoors, the harvesting window will always fall within that period. However, a few weeks will make a huge difference on the potency of the plant.

As such, even when you know how long it takes, you still need to examine the buds. To do that, you need a magnifying tool. For a small farm indoors or outdoors, a jeweler’s loupe will help you.

This magnifying glass helps check the trichomes and the pistils closely. You can see the pistils with your naked eyes, but the trichomes will need magnification.

For larger farms, you can buy a digital microscope, which will help you magnify the trichomes even more for accurate results. The microscope takes you very close to the trichomes for the best view.

If your smartphone takes clean photos and allows you to zoom very close, you can use it to take pictures of the trichomes and then analyze them later.

To know when to harvest cannabis, you need to observe the pistils and the trichomes as explained below:

Cannabis Trichomes under microscope
Cannabis Trichomes under microscope

Examining the Trichomes

The trichomes give the best indication on when to harvest. Trchomes grow on the buds of cannabis, and they have the shape of a mushroom. They are so small that you may not see them clearly with your naked eyes. Under a magnifying glass, the trichomes look like crystals on the buds. These are the substances that make weed sticky.


The trichomes you need to pay attention to have the head as that of a mushroom. There are others that look like hairs without the head – these do not affect potency, and you shouldn’t pay much attention to them. Most of the THC in the plant is in the heads of these small trichomes. Looking at the heads can help you determine when the plant has optimal levels of THC and harvest at that time.

At the early stages, the trichomes are clear, and you know they do not have significant amounts of THC. If you haven’t looked at trichomes before, you may not distinguish between cloudy and clear ones. However, after looking at a number of them, you can tell the difference.

Note that, you need to look at the trichomes and the pistils at the same time. If the pistils are still white and there is no solid bud underneath them, then you know the plant is several weeks from being ready.

Once the pistils start to change color, you can pay more attention to the trichomes.

Mature buds have milky white trichomes that look like they are plastic. At this point, the buds have the highest levels of THC and CBD.

You can harvest them at this point for the highest potency. When all or more than 90 percent of the trichome heads turn white, you know the plants are ready. If you wait for one more week, the heads will turn amber or golden. All the THC will convert to CBN and the plant will have a relaxing effect.

Does the number of trichomes indicate more THC?

It is a good sign if your plant has a high number of trichomes, but this is not always an indication of quality.

There are many classic buds that offer high potency even when they only have a few trichomes. Other strains have frosty and promising trichomes, but they have low potency.

Strains that produce a lot of trichomes are popular in most places. However, strains such as LSD and Liberty Haze produce great potency even when they have a few trichomes. You need to pick strains based on their effects and not the amount of trichomes they produce.

Checking the Pistils

Cannabis pistils are the hairs on the buds. These hairs show you the first signs that your pot is ready for harvesting. At the early stages of flowering, the pistils are white, and they stick out straight. This will show that the plant is not ready for harvesting.

During the harvesting window when the buds mature, the pistils will darken, and they will start to curl in. At this point, you will need to pay more attention to the trichomes to determine when the plant has the highest potency.

The pistils start to change color a few weeks before the buds are fully mature. At that point, the buds are still weeks from maturity. When the first pistils start to turn, the buds get bigger and denser in the weeks that follow.

You will know the buds are ready for harvesting when at least 70 percent of the pistils darken and curl in. At this point, the buds have the highest THC levels. If you wait until more than 90 percent of the pistils darken and curl in, most of the THC will convert to CBN.

There are strains that will develop new pistils when the first batch of pistils starts to darken. This shouldn’t worry you as these new pistils will darken too. However, if the buds develop new pistils for at least three times, you need to make the decision and chop up the plant.

In most instances, the pistils will darken, but they are still sticking out. In such cases, you need to wait for a little longer for them to curl in to a point that you can see the solid bud underneath. You need to pay more attention to the hairs on the bottom buds as they give a better indication of harvesting readiness.


What if all leaves on the weed die?

If your pot gets sick or stressed, it might lose its leaves. The leaves will yellow and discolor, and they will finally fall off the plant. If the leaves keep falling and the plant is not yet mature, they might affect the smell, appearance, and potency of the buds.

If the plant loses its leaves during its late flowering stage, you need to make the decision and chop it down. You can observe to see if there are any changes, and if nothing changes, chop down the plant to save the yields.

Plants that suffer heat stress might keep growing new pistils on top of the mature ones. In such a case, you need to check the mature buds for signs of harvesting.

Heat causes the leaves on the buds to yellow. Yellowing of leaves is a stress response, and you can see it clearly in affected plants.

When plants undergo stress, they make efforts to make seeds before they die. If you realize that buds have yellow leaves all around them, you need to harvest soon. If you wait for too long, the plant could lose its flavor, smell, and potency. The buds may also develop seeds.

There are strains that make it challenging to know when to harvest cannabis. Different strains have different appearances when they are ready for harvesting.

Some strains can have most of the pistils white even when the trichomes are milky white. To know when to harvest, you can talk to other growers handling the same strain as you or talk to seed manufacturers. If you start growing a new strain, you can search for pictures of how the plant looks like at its maturest stage.

Timing your Harvest for Maximum Potency

Harvest time is not definite for weed. The same strain can be ready for harvesting in different times, depending on where it grows. However, the trichomes will be your guide on when to harvest. When at least 70 percent of them turn milky white, you are ready to harvest.

But when do you start checking out the trichomes?

Consider the flowering time of the different varieties of the plants:

Plant TypeFlowering Time
Indicaseight weeks after the appearance of flowers
Sativas10 weeks with flowers
Autoflowers12 weeks from the seedling stage

Noting these durations will help you know when to pay more attention to the pistils and trichomes. You can also check for flowering information on the seeds or seedlings package.

Once you get the flowering period right, you can now observe the pistils. When the pistils turn brown, the plant is near maturity. If between 70 and 90 percent of the pistils are brown, the plant has high levels of THC and CBD.

However, pistils can change color due to environmental factors. Granted, this is why you need to observe the trichomes. If the pistils turn prematurely, then the trichomes will tell you when the buds are ready for harvesting.

If the trichomes are clear, the plant is still a few weeks from being ready. If the trichomes are milky, harvest immediately. If the trichomes turn brown, they are already overripe.

Final Thoughts on the Ideal Harvest Time for Cannabis

Besides knowing when to harvest cannabis, you need to understand how to increase its potency. Flushing, for instance, helps wash out the nutrients from the plant to make it ready for harvesting. You can also stop watering the plants for at least three days to harvesting day.

When you stop watering the plants for a few days, you stress them to increase potency. However, do dry the plant for long as it might increase resin as the last kicks of a dying plant.

Knowing when to harvest cannabis for maximum potency is as important as all the other growing steps you follow. The potency, flavor, and smell of the plant depend on the harvest period. Again, you need to store trim, cure, and store the plant right to maintain its potency.

After a few growing seasons, you will understand the strain you grow better, and you will harvest right most of the time. If you start growing a new strain, you will again need to be careful on harvest time. Pot forums, seed manufacturer’s websites, and other growers can help you get as much information about a given strain as possible.

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