Different types of plants will thrive in specific environments. Two of the most important factors that impact environment are temperature and humidity.
Temperature and humidity can also impact each other, which is why when it comes to controlling your humidity, you always need to keep temperature in mind.
Whether you are starting seedlings, rooting cuttings or drying herbs or vegetables, the humidity in your room can drastically change conditions.
Maintaining proper humidity is especially important in the early stages of plant growth. This is because younger, smaller plants are more prone to disease and environmental strain until they develop healthy root systems.
Understanding humidity in your grow
Most plants thrive in similar humidities during their various stages of growth. For example, seedling and clones/cuttings require a higher humidity because it gives them more access to moisture they can convert into growth.
As your plants develop leaves and foliage, a higher humidity can still help in the same way. Just as roots absorb water and nutrients to feed your plants, your plants can pull moisture out of the air and process it through the leaves.
Generally, plants in their vegetative stage will thrive in a humidity range of 40-60%, while seedlings and cuttings may require slightly higher, approaching 70%.
As your plants develop and enter their flowering stage, they don't need nearly as much humidity. Flowering plants thrive between 40% and 50% humidity.
There are various ways to control humidity, the simplest being a dehumidifier or humidifier. While not typically a cheap option, a dehumidifier does exactly what it should, reducing the humidity in your grow room. And humidifier, you guessed it, does the opposite.
But even with a dehumidifier, your humidity can still be impacted by other equipment, like your grow lights. Grow lights put off heat, and that heat interacts with the humidity in your room, creating something called a Vapor Pressure Deficit.
In short, the temperature produced by your grow lights and other environmental factors creates a changing process of transpiration, an essential process in plant growth. In general, a higher temperature with a lower humidity can cause problems.
But lower temperatures and more humidity is just as dangerous for your plants. That's why it's important to know what temperatures and humidity your plants need, and adjusting your environment to match.
Whether it's with de/humidifiers, fans, air conditioners, heaters, a well-designed ventilation system or a combination of them all, there's no shortage of ways to deal with humidity in your grow room.
Leaving humidity unchecked
Depending on location, for some growers indoor and outdoor, humidity might never be an issue they consider due to having natural temperature and humidity desirable for their plants. But for the majority of us, humidity is something that needs to be monitored consistently or run the risk of killing your plants.
With high temperature and not enough humidity, you create an environment perfect for pests, and your plants can easily overheat. With a lower temperature and too much humidity, your plants can develop mold, which might not kill them but makes them unsalvageable when harvest comes.
Suffice to say, there is a sweet spot when it comes to your temperature and humidity, which brings us right back to the beginning! As long as you keep an eye on both and stay on top of any issues that you start to notice, dealing with humidity in the grow can become just another step in your daily routine.