Cannabis Pre-Harvest Tips: Everything To Know (2023)

perfect time harvest cannabis

When’s the perfect time to harvest cannabis? The perfect time to harvest cannabis is when the plant has reached peak THC potency, which can be determined by checking the color of the plant’s trichomes (seen in the image above). I’ll go into detail about cannabis harvest time and related issues below. 

When Is My Cannabis Plant Ready To Harvest? 

when to harvest cannabis

Trichomes can be seen on your cannabis plant flowers when viewed under a microscope. Trichomes are what make cannabis buds appear frosty. The color of these trichomes is used to determine whether your cannabis plant has reached peak potency and is ready to harvest.

Trichome Colors Tell You When It’s Time To Harvest

perfect time harvest cannabis

Trichomes will change colors throughout the growth process. The trichomes will start out clear, then turn cloudy white, then amber.

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Clear trichomes indicate the plant has not reached peak THC levels, and is not ready to be harvested. Cloudy white trichomes signal that the cannabis plant has reached peak THC levels, and is ready to be harvested. Amber golden brown colored trichomes indicate the plant has passed peak THC levels, and should be harvested as soon as possible. 

When considering a time to harvest your cannabis plants, you should also consider the different effects a plant with different color trichomes will provide. Cloudy white trichomes will provide a more clear headed, energetic high. Amber trichomes will provide a “couch-lock” type of high. 

The perfect time to harvest your cannabis plant entirely depends on these factors. Many growers aim to harvest their plants when they see a mixture of cloudy and amber trichomes on the plant. Other growers develop a preference for one color trichome over the other. The color of trichome that you harvest should depend on what effect you want from the plant. 

One big takeaway is if you see clear trichomes, you can be confident your cannabis plant isn’t ready to harvest. You want cloudy, amber, or a mix of both, as described above. 

How To View Trichomes

perfect time harvest cannabis

There are different ways to view trichomes on your cannabis plant. The most inexpensive methods involve the lens from a laser pointer, or an inexpensive handheld microscope. If you have pets around the house, you may have an old laser pointer that has a lens under the cap which can be used to view the trichomes.

Hold or tape the lens to the camera on your phone and inspect your plant’s trichomes. It won’t be perfect but it’ll be good enough to see what you need to see. The image above is an example of what you’ll get by doing this. Make sure you’re inspecting the buds and not a frosty leaf. 

If you don’t want to be squinting and guessing from the laser lens method, you can purchase an inexpensive handheld microscope and get a much better view of your trichomes like the one below:

when to harvest cannabis

Should You Harvest Sick or Injured Cannabis Plants Early?

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I frequently see growers asking if they should try to salvage a sick or injured plant. I know it’s hard to let so much hard work go to waste. The answer really depends on the situation.

Broken Stems Or Stalks:

If you accidentally snapped a stem on your plant, try taping it back together before you panic and toss it. You’ll be surprised what these plants can recover from. I’ve definitely seen plants survive after being taped back together. Use a stick or post to support your stem then tape it as close to normal as possible. Don’t wrap the tape so tightly around the stem that you prevent any nutrients from getting through the plant.

Harvesting a Sick or Infested Cannabis Plant:  

If your plant is dying from a nutrient deficiency, overdose, or some other growing error, and you determine the plant likely won’t survive, you can try to harvest the bud, but it’s highly likely the bud won’t be full potency unless the plant emergency occurred close to harvest. If it’s too early in the flowering cycle it may not even be worth the harvesting effort. 

If your plant is infested with mold or mildew you definitely shouldn’t harvest it. Mold and mildew may be harmful to your health and there’s no way to easily or thoroughly remove it from the buds. In this situation you’ll need to take the loss.

If you have bugs in your cannabis plants, it depends on the severity of the infestation. You may choose to spray your plants with a natural insecticide like molasses to kill off the bugs, then wash off any remains. 

Cannabis Plant Taking Long Time To Reach Harvest:

perfect time harvest cannabis
Phone Home by Bodhi Seeds: Estimated Time To Harvest – 16 weeks

This is another frequent concern I hear from other growers. What’s wrong when the breeder claims a seed will take 12 weeks total to harvest and your plant is on week 10 and just started flowering? 

The answer can be several things. First, the number of weeks to harvest provided by a breeder or seed retailer is just an estimate. Don’t panic if your plants aren’t ready exactly when the breeder estimated. Cannabis plants frequently take longer time to harvest than a breeder’s estimate. This can be especially true if your growing conditions are such that a plant may have been stressed throughout the grow. 

Which Type of Cannabis Plants Take The Shortest and Longest Time To Harvest?

Many indica and hybrid strains are ready to harvest six to ten weeks after beginning the flowering stage of growth. Those plants are quicker to harvest compared to pure sativa strains. Pure sativa plants take up to 4 months to reach harvest once the flowering stage of growth has started. Hopefully this helps you decide on a quality strain to grow.  

Should You Flush Cannabis Plants Before Harvesting?

The short answer is it’s not entirely necessary to flush cannabis before harvest, but flushing cannabis before harvesting has been and continues to be the preferred practice among a majority of cannabis growers. 

A recent study showed that cannabis consumers couldn’t tell the difference between flushed and unflushed cannabis. The study also said that some consumers even preferred the flavor profile of the unflushed cannabis to the flushed cannabis. Last, analysis of flushed and unflushed cannabis did not find any significant difference in nutrient levels, yield, potency, or terpenes. 

The main reason growers typically flush cannabis or use clearing solution before harvesting is to clear the plant of any remaining chemical nutrients. If you’re running an organic grow, there’s no reason to flush your plants before harvesting. If you’re using inorganic nutrients, you still may not need to flush the plants unless the cannabis plants have been fed a relatively high amount of nutrients. 

How To Flush Cannabis Plants Before Harvesting:

If you prefer to flush your cannabis plants prior to harvest, you would do so by watering a normal amount with plain pH adjusted water or clearing solution 10 to 14 days prior to your estimated harvest date. You should expect your plant leaves to turn yellow leading up to the harvesting date.This is normal and not cause for concern. 

If you decide to feed your plants up until harvest, products like Flawless Finish will help you clear out the plants in a very short period of time. 

Avoid Watering Immediately Before Harvesting Cannabis To Speed Up Drying:

Avoid watering your cannabis plant in the days immediately prior to harvesting. This will help a speedy drying process. If you water every other day, skip the watering two days before your harvest date. Don’t allow your plants to wilt, but safely cutting back on water immediately prior to harvest will be an added convenience. 



My name is Nick, and I'm a home grower who spends time writing about indoor growing tools and setups. My goal is for 420ExpertGuide to be a one stop shop for indoor growers to find the information they need.