How to Prevent Bud Rot Using Dehumidifiers

by | Jun 22, 2022

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Bud rot is a prevalent fungal disease, also known as gray mold or botrytis. When it comes to cannabis cultivation, it’s known as bud rot, as it most commonly affects buds, causing them to rot, though it can develop on any part of the plant.

Like other mildews, bud rot develops under humid conditions. So, the most effective way to prevent bud rot is by using dehumidifiers to maintain low humidity levels. 

Why Bud Rot Is a Problem for Cannabis Growers

When bud rot infects a plant, it slows its growth and development. In many cases, it can go as far as causing the plant to shrivel and die. The best option is always to prevent bud rot before it starts.

prevent bud rot

Once an infection begins in a closed growing space, it can quickly spread to the entire facility. This makes bud rot challenging to deal with once it breaks out. So it’s much more effective to prevent it than treat it after the fact.

However, cannabis regulations make things even more complicated. Selling or distributing buds that contain mold is illegal, including for further processing, such as manufacturing edibles, extracts, topicals, etc.

Regulations surrounding cannabis production don’t just inhibit the presence of mold but also the use of fungicides. Common sprays used to prevent gray mold are toxic. Therefore, growers can’t legally use them on their cannabis crops. Without being able to rely on sprays, prevention becomes the only viable course of action.

It’s important to note that bud rot can develop during any stage in the production process, including post-harvest and even inside the final packaging. So it’s imperative to ensure the conditions that prevent bud rot during every part of production.

How Bud Rot Develops

Cannabis plants constantly transpire water through the leaves. So, in a closed grow room or greenhouse, humidity levels are constantly being pushed upwards. When relative humidity reaches 100%, water condenses on surfaces, often on the plants themselves.

Cannabis buds are incredibly dense. So the moisture they release can get trapped inside the bud, making it one of the first places for water to condense. This condensation is why cannabis is especially susceptible to bud rot and why growers aim for a very low humidity level, much lower than most crops.

How to Prevent Bud Rot

Cannabis cultivation is highly regulated, often requiring environmental measures to prevent mold. The use of common fungicides is also mostly inhibited, so growers are left with only one option – to prevent bud rot before it can develop.

Prevent Bud Rot with Dehumidifiers

The only way to completely prevent bud rot in a way that’s fully compliant with regulation is through climate control. More specifically, by controlling humidity and maintaining low levels of relative humidity.

The easiest, most effective, and most efficient way to control humidity, is by using dehumidifiers. Dehumidifiers such as DryGair’s DG-X are explicitly designed for cannabis cultivation, making them extremely effective and highly efficient at their task of preventing bud rot.

Creating Climate Uniformity

Another critical factor when it comes to preventing bud rot is uniformity. Climate uniformity means maintaining the same conditions, such as temperature and humidity, throughout the entire grow space. Local pockets of humidity, called microclimates, are extremely common in crowded cannabis growing facilities. So preventing the formation of microclimates is crucial for mold prevention.

Bud rot doesn’t take much to develop and spread. It’s enough for one plant to experience high humidity for this fungal disease to take hold, create spores, and infect other plants. So, keeping humidity levels low isn’t always enough. Growers need to ensure low humidity everywhere, at all times. This is where uniformity comes into play.

DryGair’s dehumidifiers, for example, come with a unique, patented air circulation system that tackles this issue. The unit’s fans expel the dry air in all directions at once, with enough force to cover the entire space. This creates a circulation of air that ensures similar conditions all around the space, dispersing local microclimates and contributing to homogeneous conditions, as well as buds.

Dehumidification Vs. HVAC

Many growers choose to pass on dehumidifiers, opting to rely on HVAC systems instead. The reasoning behind this choice is understandable. HVAC systems, or other forms of air conditioning, are necessary for cannabis cultivation anyway. So growers “cut corners” by utilizing them for humidity control, as well as temperature.

HVAC systems do remove some moisture from the air as a side effect of their operation. But they’re not designed for the task and aren’t as efficient as a dedicated dehumidifier. In order to control humidity at all times, HVACs need to run constantly, often alternating between heating and cooling, just to keep removing humidity, even though temperatures are already within the ideal range.

So, relying on HVAC for humidity control is problematic, driving growers’ costs up, especially when energy prices are high.

Additionally, because HVACs aren’t as efficient as dehumidifiers, it takes a much larger system to deal with the massive amounts of moisture cannabis creates. This means growers need to install oversized systems that would be considered overkill if meant for temperature control alone.

The most efficient way for cannabis growers to control their environment is to combine HVAC and dehumidifiers. They can get by with a much smaller HVAC system, running less often, which means less maintenance and lower operational costs. The dehumidifiers can then take care of humidity, regardless of the HVAC’s operation.

By combining dehumidifiers with HVAC, growers can separate humidity from temperature control and save a lot of unnecessary expenses and can help prevent bud rot in your grow.