Whether you’re growing a few plants for personal use or setting up a commercial cannabis farm, your dry room is crucial to the success of your operation. The dry room is where the fresh flower turns into a dry, usable product. A good dry room setup can let you finish your crop beautifully and easily, but a poor dry room setup can ruin your crop by promoting mold growth that destroys the buds.

While most of the potential complications with drying can be mitigated by diligent attention to your HVAC settings, it’s important to understand what happens during the process so that you can nip any potential problems in the bud.

What Goes On In A Dry Room

Once you’ve harvested your cannabis crop, you need to dry it. In the dry room, harvested plants are suspended upside down and allowed to slowly die and dry over a fifteen-day period. This has the benefit of preserving the buds and, importantly, killing off the chlorophyll. If your crop isn’t properly dried, it will taste like hay, which is not what you or your client base want. Improperly dried cannabis will also be less potent and have fewer terpenes and cannabinoids remaining in the flower.

The drying process is simple if you have a good dry room. All you need to do is place the harvested plants upside down, either suspended from a rack or a clothesline. The choice of rack or line depends on how much you need to dry and how much you want to invest. Racks are more expensive but are better for large quantities of cannabis. You can also dry on screens or a solid surface, but if you do that you need to rotate the buds while they are drying, and minimal handling is best for the preservation of trichomes.

No matter how you position them, your plants need about two weeks to dry properly. The drying process requires darkness and stable conditions. Keeping the cannabis dark helps destroy chlorophyll. You also need good airflow that is neither too weak nor too strong. Insufficient airflow will promote mold, but airflow that’s too strong will dry your buds too fast.

After the drying stage, you will have dried flowers that can then be packed into curing jars. You’ll know that they’re ready when the buds are relatively hard to the touch and the twigs bend without cracking completely. The chlorophyll taste and smell should be gone, leaving that characteristic aroma of finished cannabis. The drying stage is crucial to the strength and usability of the crop, and a good dry room can solve many problems.

Where Can The Dry Go Wrong

There are several places where the drying stage can have problems. The first is the pre-drying trimming stage, and errors can occur throughout the process. Avoiding these common errors means that you’ll have a better crop yield with more potent THC.


Before you dry your plants, you have to decide whether you want wet trim or dry trim. If you do a wet trim, you’re trimming off the leaves before drying. A dry trim happens after the drying process. There are advantages and disadvantages to both, but when you look specifically at the relationship between trimming and drying, you need to consider that wet trimming leaves less vegetable matter to dry. This means your buds will dry faster if they’ve been wet-trimmed, sometimes in as little as 10 days. Dry trimming is fine, but you may need to leave your buds a little longer.

Handling and Inspection

You should handle your buds as little as possible when hanging them to dry, as friction leads to trichome loss. However, you also need to inspect the buds visually for powdery mildew or other fungal infections before you dry. Even the best dry room conditions can still allow fungal growth to ruin your crop if there’s already an infection before the process starts.

Dry Room Conditions

Once the buds are in the dry room, the success or failure of your drying stage can be linked directly to your mechanical setup. The most common issues with the dry room setup are heat, light, and humidity. If your setup is too hot and too dry, you can get the fast-dry phenomenon that essentially turns your crop into hay. It’s still usable, but not pleasant.

Too hot and too wet leads to mold and fungal growth, which means contamination— which then means tossing the whole batch. Light is another issue. Constant exposure to light can damage the THC content of your crop and preserve the chlorophyll content. If you go in to check your drying plants, you should use a flashlight for the best results.

When it comes to dry room conditions, you have an incredible amount of control– provided your system is well-maintained. Human error can happen in trimming, handling, and inspection, but unless you have a power outage or equipment malfunctions, you shouldn’t have to worry about drying problems due to mechanical failure.

Setting Up The Perfect Dry Room

Now that you understand what needs to happen and what can derail the process, let’s talk about ways to build the best dry room for optimum crop finishing. Some small-scale growers use grow tents or closets, but if you’re serious about cannabis farming, a dedicated dry room can boost your operation.

However, it is important to remember that many seasonal variables can affect your drying stage. Seasonal temperatures, elevation, fluctuations in humidity levels, and even barometric pressure changes can all affect how fast your crop dries. Additionally, different cultivars can have differences in moisture content, and so one harvest to the next might be different depending on what you’re growing.

That said, if your dry room is properly ventilated, and if you have the ability to both heat and cool it, as well as increase or decrease humidity, you will have enough control over your drying process to ensure a successful finish to your crop every time.


You want your dry room to be fairly cool so that your plants dry slowly and uniformly. A temperature of 68ºF/20ºC is ideal for your dry room. You want to avoid going over 75ºF/24ºC, as this will dry the buds unevenly and far too quickly.


If your room is too humid, your buds will not dry. But if your room is

dry, the flowers will not dry uniformly, leading to a crumbly outside, a too-damp inside, and a reduction in terpenes due to evaporation. You want to keep your humidity between 40% and 50%, to get your plants’ moisture content down to around 20%. Some growers prefer to dry between 50% and 60%, which is often advisable at higher elevations.

Air Flow

A good dry room has light, fresh air flowing into it, but not directed directly at the flowers. If you use a fan, point it at the floor or ceiling away from the drying buds. That way, the harvest doesn’t dry out too quickly, which leads to a harsh taste. An airflow limiter can be very helpful here. You also want to control the odors in your exhausted air, which is best done through filtering, either through carbon filters or another medium.

If you’re interested in setting up the perfect dry room, don’t hesitate to reach out to us. At Vulcan Squad, we’ve been in the business of optimizing your growing operation for over a decade. We’re nationally licensed contractors whose business is your business, and our industry knowledge lets us optimize your facility. Schedule a consultation with us today!