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When is the Best Time to Harvest Autoflowering Cannabis?

Dark Pistils? Cloudy Trichomes? We detail what you need to look for before you harvest your Fast Buds.
2 years ago
4 min read
When is the Best Time to Harvest Autoflowering Cannabis?


It's been ten weeks since you dropped your germinated autoflower seed into its pot. The plant is in bloom and smells heavenly. Time to cut it down, and harvest your buds, right? Not so fast. Harvesting too early will hurt the potency of your final product, but so will harvesting too late. What's a stoner to do? Follow this guide from Fast Buds, and you'll get the best buds possible every time.

Don't Forget to Flush

Fast Buds' Blue Dream Before and After Flush

Fast Buds Blue Dream'Matic Before and After Flush


The first step to harvesting your delicious autoflowers is 'flushing' the plant. We'll go into more depth about how and when to flush at another time, but the here's the gist: you stop feeding the plant and give it only plain water for a period before harvesting. This gives the plant time to use all the remaining sugars and nutrients its storing. If you don't flush, excess amounts of both end up in your final product, and they burn alongside your bud, giving it a harsh feel and flavor. How long you flush depends on your growing medium, but the result is the same. Flushed weed is incomparably smoother.

When to start your flush is up to you, but one sure sign an autoflower plant is ready to go on a terminal diet is yellowing leaves. If your fan leaves have been lush and green throughout, the first signs of yellowing let you know its time to begin the harvest process and start flushing.

Pistil Whip

Fast Buds' Stardawg Showing Pistils Curling In

A Stardawg Autoflower with curling pistils


The first things you'll want to keep an eye out for are your flower's pistils. These long, hair-like organs on the surface of the bud usually start out whitish-green and darken to brown and red as time goes on. For maximum THC you'll want to harvest when around 60%-70% of your plant's pistils have darkened and started to curl in on themselves. If you wait a touch longer, until 70%-90% of the pistils have begun to curl, your buds will be lower in THC, but more abundant in other cannabinoids, which makes the bud more likely to give you the munchies and lock you onto the couch for hours. If you're growing a sativa, you'll want to harvest at the 60%-70% mark, but if you're hoping to collect an strong Indica, waiting a bit can enhance what we traditionally think of as 'Indica' effects.

This method is easy to do and requires no specialized equipment, but it's not the most accurate or reliable. New pistils can appear overnight, setting your time to harvest back days. Some strains are more prone to producing dark colored pistils, regardless of how ready to harvest they are. However, if you want to be more accurate, you're going to need the right equipment.

The Right Stuff

Fast Buds Blackerry Kush Trichomes

Tricomes from Fast Buds' Autflower Blackberry Kush on the bud and close-up


In order to be more accurate than the pistil method, we're going to have to look at the trichomes, the sticky balls of resin you see on well-grown bud. These specks contain most of the THC and other cannabinoids your planning to smoke.

A simple magnifying glass should be enough for most people to get a good view of their plant's trichromes. Serious growers, however, will probably want to go the extra step of investing in a high-quality jewelers loupe to get a better view. Professional growers take that even further and often use digital microscopes to get the best view of their buds. Depending on the laws where you live, you might have seen these microscopes at your local dispensary or cannabis club. Customers can use these to confirm their weed is properly grown and harvested before purchasing.

The Trichome Clock

Fast Buds Green Crack Trichomes

Tricomes on a Fast Buds' Green Crack Autoflower


Under magnification, trichomes take on the appearance of mushrooms made from crystal clear blown glass. As the plant nears harvest time, their transparent appearance will grow cloudy. The difference between a clear trichome and a cloudy one is subtle. If this is your first grow, it will take your time to learn to tell the two apart.

When most of your trichomes are cloudy, your plant is ready to harvest. If they've gone from cloudy to amber, you're still OK, but some of the THC will have converted to other cannabinoids like CBN, which will change the effects you receive when smoking. Again, this isn't usually a problem if you're aiming for a strong indica feel, but if you were hoping for an active strain, it's best to error on the side of harvesting early.

With These Powers Combined...

Knowing when to harvest isn't an exact science, but these rules of thumb should steer you in the right direction. For best results, you should combine the two methods described above. That means if you're shooting for high-THC buds your should harvest when 50%-70% of your pistils have changed color, and most of the trichomes have turned cloudy but not amber.

We hope this guide helps you enjoy growing faster. Don't forget to check our Facebook and Instagram feeds for all the latest strains, deals, and growing tips from Fast Buds.

Harvest it right with best Fast Buds strains:

Gorilla Glue Auto
Gorilla Glue Auto
Gorilla Glue autoflowering
9-10 weeks
Very High
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