Complete Guide to Use a Humidifier for Houseplants

Some of the most popular houseplants are from tropical climates and therefore thrive in areas with high humidity. If the air in your house is dry, such as during the winter months, your plants may benefit from the use of a humidifier.

Compared to misting or using a pebble tray, a humidifier will provide a more constant humidity level for your tropical houseplants.

For best results, run your plants’ humidifier for a few hours every day between sunrise and midday. The humidifier should be in the same room as your humidity-loving plants but not so close to them that moisture starts to condense on the leaves.

When in doubt about your home’s humidity level, use a hygrometer to get an exact measurement. Different plants have different preferred ranges, but most will be happy in a range between 40% and 60% relative humidity.

Why do Houseplants need a Humidifier?

Except for succulents and cacti, many popular houseplants thrive when there is more moisture in the air. Plants like orchids and aroids (like peace lily and Monstera), just to name a few, are more acclimated to a tropical climate. 

Unlike succulents, which store water in their fleshy leaves, these tropical plants are not used to lower humidity. 

Warm Mist Humidifiers

Warm mist humidifiers work by using a heating unit to bring the water inside up to a boiling temperature, turning the water from a liquid into a vapor. 

Because of the way the mist is created, only pure water leaves the device. Any minerals in the water are left behind in the water tank, and the risk of germs or bacteria is reduced. 

Warm mist humidifiers do not use a fan to propel the water vapor, meaning they are a little quieter than the other two kinds. However, the heating element requires more electricity and can be dangerous for curious kids and pets. 

Ultrasonic Humidifiers

Ultrasonic humidifiers do not use a heating element to turn the water into vapor. Instead, they use a vibrating plate to create a cool mist. 

The lack of heating element means there is a greater chance for bacterial buildup in an ultrasonic humidifier. Also, anything dissolved in the water will be carried with the mist. For this reason, it is always recommended to use filtered or distilled water when using an ultrasonic humidifier. 

Evaporative Humidifiers

Like Ultrasonic humidifiers, Evaporative humidifiers also create a cool mist. However, it is created differently. In this type, there is a filtering wick that absorbs water from the tank. Then, a fan blows over the wick to cause the water to evaporate into the air. This creates an invisible vapor. 

This humidifier is nice because it filters the water as it works, although the fan might be a little noisy. There is also no risk of getting burned from a heating element. 

Evaporative humidifiers are unable to oversaturate the air. If the air already has enough moisture in it, the water simply will not leave the wick due to physics and chemistry principles, no matter how much the fan blows. This is great for folks who might forget to turn off their humidifier. 

You do need to make sure to replace the wick regularly to prevent bacterial buildup. 

Warm vs. Cold Mist: Which do plants love more?

There will not be a big difference for your plants whether you use a warm mist or cool mist humidifier. The warm mist humidifier may warm up your room a little bit, but the effect will be negligible. The ultrasonic humidifier may cause some minor white, powdery buildup in the room, including on your plants, if you do not use distilled water. 

Beyond that, the specifications that matter most have less to do with what kind of mist is produced and more to do with how long the humidifier can run and how big of a room it can service. That’s what we will discuss next!

Room Size

Like any appliance that affects the air in a room, such as a heater or air conditioner, different humidifiers will have a different room volume capacity. If you only have a small shelf of plants, you may only need a small diffuser. But if you have a huge room for your tropical plants, you will need either a powerful humidifier or perhaps two smaller ones. 

Run Time

You wouldn’t want your humidifier to run out of water before it is done providing humidity to your plants! When looking for the best humidifier for your situation, you should look for one with a longer run time, which usually goes hand in hand with a larger water reservoir. 

Noise Level

The noise that your plants’ humidifier makes may or may not matter much to you (your plants certainly won’t know the difference), but it is definitely something worth considering when making a new purchase. 

Evaporative cool mist humidifiers will generally be a little louder due to the fans used to distribute the water vapor. If this would bother you, you may want to go with an ultrasonic cool mist or a warm mist humidifier. 

Large and easy to clean tank system

You will need to clean your humidifier frequently, so you should consider purchasing one that is easy to take apart and clean. 

A larger tank is also better than a small one as you will not have to refill it as often. Some units have a convenient top-fill design, which makes it very easy to refill. 


The final thing to consider when looking for a humidifier for your plants is its aesthetic design. This is something that will be placed in a noticeable area in your room; you shouldn’t purchase something you don’t want to see!