The latest LED and plant growth information from our specialists


The ideal humidity for growing plants indoors

Managing humidity in your grow tent

Indoor plants are more prone to disease and crop failure because they are grown in an artificial environment. In the wild, outdoor plants grow in conditions balanced by nature. Inside a grow tent, you must replicate that balance.

Lucky for you, all the hard science work is done and you just have to keep your plants within the recommended ranges from the chart below.

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Ideal humidity for growing indoor plants

The best humidity range for your indoor plants will depend on the ambient temperature. These two values need to be in balance for the plant to have the best growing conditions.

As you can see from the chart below, at high temperatures the sweet spot for humidity is narrowed down. This makes lights that run hotter like HPS bulbs an issue for grow tents. They are less forgiving. You can however push the humidity higher with the higher temperatures. But are HPS lights waterproof? No.

LED grow lights like the Fohse grow lights on the other hand are IP65-IP67 rated for waterproofing making them the ideal, safe grow lights.

High humidity and plant health effects

If your grow tent humidity is outside the goldilocks zone your plants will suffer. Any higher, say 95% at 25 degrees then you are at high risk of Fungal Pathogens causing problems with your indoor plants.

If the humidity is too low then your plants will transpire a lot and you run the risk of leaf burn from your grow lights and stunted growth.

Learn how Mycorrhizal Fungi can help defend your plants against pathogens.

Solving grow tent humidity problems

To keep your grow tent humidity in balance with the temperature, you could monitor it every hour and adjust your peripherals like fan and humidifier manually OR you could automate this problem away with smart sensors and controllers.

Inkbird has a range of products to help with controlling your peripherals and in turn, tent humidity. Check out the full range here – all with free 3 day shipping