How to Use A Humidifier for Houseplants

humidifier for houseplants

If you’ve got tropical or exotic house plants at your home, you’ll have to ensure sufficient humidity for them to thrive. Using a humidifier would be more effective than a mister to provide constant humidity for these plants. Ferns, calatheas, monsteras, philodendrons, or any other humidity-loving plant require anywhere between 40-60% relative humidity. In this post we’ll go over everything you need to know on how to use a humidifier for houseplants.

Indoor Plants That Need Extra Humidity

humidifier for houseplants

Before looking into how to use a humidifier for houseplants, let’s have a look at the plants that benefit from increased humidity levels. The use of a humidifier will help simulate the natural environment they thrive in. 

  • Boston Fern: You could keep one of these in your bathroom, where the humidity levels usually are higher. 
  • Alocasia: Requiring about 70% humidity level, it stands out with its striking arrowhead leaves and bold patterns.
  • Air plants (Tillandsia): These plants need moisture in the air for hydration since they aren’t rooted in soil.
  • Bamboo: This common house plant, with its delicate leaves, can thrive in your bathroom and in low-light conditions too.
  • Bird’s-nest fern: Just like any other fern, this one loves humidity and can manage with low-light levels; good to keep in your bathroom.
  • Orchids: Needing about 40-70% humidity, they don’t need to be watered a lot; so humid and not wet are the ideal conditions for these beautifully blooming plants.
  • Dracena: This is one to suit any setting, with its lovely spiky leaves. 

Humidifiers for Houseplants

There are three types of humidifiers you could get. The deciding factor should be what works best for you and your plants.

Warm Mist Humidifiers

These devices contain a heating element to evaporate the water, thus turning it into vapor. This means that bacteria and germs get killed in the process, ensuring that pure water leaves the device. Also, frequent cleaning wouldn’t be required because of this. Warm mist humidifiers create slight heat, making it ideal for tropical plants to thrive.

The negatives of these devices include the risk of burns to pets or children and higher electricity consumption.

Warm Mist vs. Cool Mist

There are humidifier models that can dispense cool mist or warm mist. While both kinds of humidity are acceptable, each has pros and cons. For example, the warm mist may not make the place comfortable for you, while your plants will be warm, comfortable, and hydrated. 

On the other hand, cool mist devices make the room quite chill, even your plants. Unfortunately, this could eventually lead to mineral build-up on them, which isn’t beneficial to plant health.

Ultrasonic Humidifiers

Ultrasonic Humidifiers

A vibrating plate in the ultrasonic humidifier creates a cool mist to adjust the relative humidity in the room, and a small fan blows out the vapor. The chances of bacterial and mold buildup in these devices are higher, requiring them to be cleaned frequently. 

Neglecting regular cleaning will result in mold spores and bacteria dispersing into the air with the mist. This could infect your plants, causing harm, as mold kills plants quickly. An infected plant can also spread the infection to nearby plants.

Evaporative Humidifiers

The cool mist that evaporative humidifiers create is through a filtering wick which absorbs the tank water. A fan blowing over this wick evaporates the water into the air, creating an invisible vapor; the water gets filtered as it works.

These humidifiers cannot oversaturate the air, especially if there is enough moisture present in the air. The principles of physics and chemistry used in these devices will stop the water from leaving the wick, regardless of how much the fan blows. If you’re one of those people who tend to forget to turn off the humidifier, this could be a good option. The wick will need to be replaced regularly to prevent bacterial buildup.

How Big A Humidifier is Needed?

The typical humidifier models are available in 30-pints, 50-pints, and 70-pints. If you intend to use the humidifier only for your plants, you could go for the smaller ones. This would also depend on how big your room is. The square footage coverage is specified with the humidifier models. A small shelf of plants could do with a small one, while a huge room with tropical plants will need a powerful humidifier or maybe two smaller ones.

There’s nothing like a plant humidifier model on the market, which is why any regular humidifier that you already have would work perfectly fine for your plants.

Best Practices for Plant Humidifiers

If you’re wondering how to best use this device for your tropical house plants, here’s a quick guide:

What is The Ideal Time to Use A Humidifier?

Ideally, the best time to turn on your humidifier for your house plants would be in the morning, between sunrise and midday. This is when they absorb the most moisture, keeping them adequately hydrated. 

Upon checking the humidity levels with a hygrometer, if it still seems low, you could leave the humidifier on slightly longer into the noon. However, it would be best not to run it late evening or at night after sundown as too much moisture during the night could negatively impact the plants’ natural transpiration (breathing). Unless the room feels extra humid, using the plant humidifier daily is beneficial to keep your plants healthy and hydrated.

Running the humidifier for about three to five hours a day should suffice to build up the relative humidity to hydrate your plants. Suppose the room feels damp, then using it for a lesser time, for about two to three hours, would do. On the other hand, if the room feels dry despite running it for the recommended five hours, another extra couple of hours would help build up the moisture.

Where to Place A Humidifier?

Where to Place A Humidifier

Keeping the humidifier in the same room as the plants works well. Your plants need their breathing space, too, so placing it about four to six feet away will ensure sufficient absorption of water vapors without turning them soggy or weak. Some humidifiers come with a spout or hose hanging over your plants to direct moisture toward them for better absorption.

You could consider keeping a small table in the center of the room to place the humidifier in an elevated position. This will help disperse the moisture evenly throughout the entire room.

Filling it Up

Humidification of plants needs to be done using distilled water. The use of undistilled water causes a mineral build-up in the humidifier as well as on plants and the surfaces around. This will eventually make your plants weak. 

Using impure water is even worse, as it adds toxins and other harmful substances that might not be good for the plants. The best options are distilled or filtered water.


Regular cleaning of humidifiers ensures safe and clean dispensing of moisture around it. If you neglect regular cleaning, the result would be the presence of bacteria and mold that will harm you and your plants. 

Using antibacterial or antimicrobial substances for the cleaning process is ideal, including peroxide, a teaspoon of bleach, or a cup of distilled white vinegar. The water tank must be cleaned thoroughly using a warm water solution, and any residue on the inside must be scrubbed off. 

Final Thoughts

While most house plants survive within normal indoor conditions, keeping your tropical house plants thriving needs a good amount of moisture in the air. A humidifier takes care of this by raising the humidity level around it effectively. If you live in a dry climate zone, you can ensure your plants get sufficient moisture with this device around them. We hope you have enjoyed this article on humidifiers for houseplants and be sure to leave a comment below with any questions!

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