Lack of humidity also poses the possibility of plant desiccation, where the plant becomes exposed to infestation by insects such as molds, white powdery mildew, and spider mites.
Indoor gardeners naturally invest in a digital thermometer and hygrometer to help them track readouts.
This is why you must raise the humidity in a grow tent. This can be achieved by relying on a humidifier or simple tricks using materials found in your home.
On the contrary, the relative humidity in a grow tent will elevate once you start adding plants, especially large ones, because they respire more and produce more relative humidity.
- Clones or seedlings prefer 74-78 degrees Fahrenheit.
- Vegging plants prefer 70-78 degrees Fahrenheit.
- Flowering plants prefer 88-75 degrees Fahrenheit.
- Harvesting phase normallyrequires 65-74 degrees Fahrenheit
Bear in mind that controlling humidity means considering other indoor gardening aspects such as temperature, ventilation, and light.
To attain high humidity in your grow tent, gardeners simply increase an air-conditioner’s temperature or reduce the temperature of the heater.
Moreover, fans let the air circulate well and get distributed to your growing plants. As a result, you can avoid harmful microorganisms such as fungi and bacteria from increasing or staying inside your tent when there’s proper circulation of air.
When your bigger plants respire, they release products such as carbon dioxide and water vapor, thus feeding their smaller counterparts.
Lindsey Hyland grew up in Arizona where she attended University of Arizona’s Controlled Environment Agriculture. She supplemented her education by working on various organic farms in both rural and urban settings. She started Urban Organic Yield to discuss gardening tips and tactics. Growing and raising just about anything gets her very excited. She is especially passionate about sustainable ways to better run small-scale farms, homesteads, urban farming and indoor gardening.
As simply as possible, relative humidity (RH) is the amount of water vapor possible in the air at a certain temperature – expressed as a percentage. The higher the temperature, the more vapor it can hold. So it stands to reason, the lower the temperature the less it can hold. Understanding this is important to knowing how you can address RH in your growing space.
A higher RH in the early going keeps a plant healthy while the roots are developing and promotes vigorous growth which will translate to higher yields later. This is why some growers choose to start their seedlings in propagators.
Hang Wet Towels or Sheets
If you’re happy with the temperatures in the room, then adding water vapor may be a better option. Hanging towels is not a long-term solution and rings of a basement/garage method, but your plants don’t care where the RH came from. This can help out in a pinch.
The importance of controlling a grow room’s climate can’t be stressed enough. This is true for every indoor garden, from the garage-scale operation to the largest of warehouses.
In most cases, RH problems arise in young plants and seedlings with underdeveloped roots. This is because the plant can’t yet take up enough water to support itself, so most of its water intake comes through the leaves. If humidity levels are too low you’ll end up with leaves curling upward like little spoons. Or, if roots are a bit more developed, low RH will make the young plant drink excessively which will often lead to “nutrient burn,” characterized by brown tips on your leaves.
Since nobody in their right mind goes into production seeking to grow low-quality flowers, we’ll assume you’ve invested in proper lights, ventilation, dehumidifiers and AC units. However, what gets lost in the mix sometimes is a controlled way to introduce humidity into a space.
Add Larger Plants to the Room
Larger plants perspire more than seedlings which will increase the overall RH in the room. This option may not be for everyone, especially where garden space is at a premium.
RH has a sort-of yin yang relationship with temperature in that raising or reducing it has the opposite effect on RH. Raise the temps with the same amount of water vapor in the air and RH goes down, lower the temps, RH goes up.
Knowing this, that means we have two different ways to increase RH, either:
A) Increase the amount of water vapor in the air without affecting temperature, or
B) Lower temperature with no change to existing water vapor
Here are 5 great options to help raise humidity in your grow room to promote vigorous growth and healthy, happy cannabis plants with increased yields!