Get weekly gardening tips and discounts!

7 Best Plant Humidifiers for 2021

A humidifier adding water vapor to the air in front of four potted houseplants

(This post may include affiliate links. While buying items through these links won’t increase your cost at all, we may receive a small commission that helps keep this site up and running. Click here for more details)

Some plants need a little extra moisture boost in the form of humidity. And for those situations, the MistAire Ultrasonic humidifier from Pure Enrichment comes in as our top choice. 

But it’s not the only good option out there!

In this article, you’ll learn about 7 of the best plant humidifiers. You’ll also find the answers to common questions and tips for choosing the humidifier that’s best for your needs. 

Ready? Let’s jump in! 

RELATED: Check out our post on 17 Best Self-Watering Planters to find a happy and low-maintenance pot for your houseplants!

Thanks to a combination of smart design and useful features, this option from Pure Enrichment comes in as our choice for the best humidifier for indoor plants.

One unique feature about the MistAire is the 360-degree rotating mist nozzle. This lets you direct the vapor in a particular direction if you choose, so it could be helpful if you want to give one plant a little extra moisture boost. 

Two mist settings let you choose the one that best suits your plants’ needs. On the high setting, this humidifier generates 150 ml per hour, and you’ll get about 16 hours of runtime between refills.

The lower setting produces significantly less mist but also offers a longer runtime. This setting can be a great way to add just the right amount of water vapor to a very small growing area.  

Like most humidifiers, the MistAire has a bottom-fill tank. This means that you refill the humidifier by:

  1. Removing the tank from the base
  2. Flipping it over
  3. Adding water through a hole on the bottom of the tank
  4. Flipping the full tank upright and replacing it in the base

Refilling a bottom-fill tank can be a sloshy, leaking process. But the MistAire has a couple of design elements that make it easier to work with. 

First, the tank holds 1.5 liters, so it’s pretty small and lightweight. 

Also, the curved tank shape does more than just add visual interest. Even if the outside gets a bit wet, the flared shape fits easily into your hands and helps prevent slips and sloshes during transport.

Pure Enrichment also offers an outstanding 5-year warranty, which is significantly longer than you’ll find with most other humidifiers.  

Upkeep is a fairly easy process, and the MistAire comes with a small cleaning brush for reaching into tiny spaces.

One problem is that the tank opening is small, making it hard to reach inside. So be sure to use white vinegar as an extra regular cleaning step. 

  • Humidifier type: Ultrasonic
  • Best for small, medium or large room: Small and medium rooms
  • Tank capacity: 1.5 liters
  • Approximate runtime: Up to 16 hours
  • Automatic shut-off: Yes
  • Product weight (empty tank): 2.27 pounds
  • Product dimensions: 8 inches long,  6 inches wide and 9 inches tall
  • Warranty: 5-year warranty

Pros

Cons

2. Levoit Cool Mist Air Vaporizer

This option from Levoit is another contender for the best small humidifier for plants, mainly due to the combination of compact size and three mist levels. 

The lowest mist setting runs for about 24 hours between refills and is ideal for small rooms up to about 100 square feet. Choose the medium setting if your room is a little larger, and expect to get about 13 hours of use. 

At the highest setting, this humidifier produces a heavy vapor that’s likely to be overkill for plants, unless you’re growing in a very large open space. If you do use the high setting, plan to refill after about 9.5 hours. 

You’ll be hard-pressed to find a humidifier that runs quieter than this one. A small hydraulic fan produces a steady mist, while the silencer dampens noise down to 24 decibels. To give you a comparison, you create about 20 decibels of sound when you whisper. 

Even though it’s a small piece of equipment, this humidifier generates a powerful, tall mist spray. Water droplets descend on your plants in a manner that mimics nature, and your flooring or tabletop also stays drier. 

One downside is the refiling process. Some people have reported problems with leaking at the tank connection point, especially if they overfilled it a bit. So be sure to watch your water level carefully. 

  • Humidifier type: Ultrasonic
  • Best for small, medium or large room: Small and medium rooms
  • Tank capacity: 2.4 liters
  • Approximate runtime: 24 hours on low setting, 13.3 hours on medium setting and 9.6 hours on high setting
  • Automatic shut-off: Yes
  • Product weight (empty tank): 2.5 pounds
  • Product dimensions: 8.5 inches long, 6.7 inches wide and 10.2 inches tall
  • Warranty: 1-year warranty, 2-year extended warranty available

Pros

Cons

3. Honeywell HUL520B Mistmate Cool Mist Humidifier

Thanks to its compact size, this humidifier won’t tower over small plants or take up too much space. And if you need to clear the table or countertop, the easy-grab handle makes moving your humidifier a breeze.

An adjustable output dial lets you set just the right amount of mist for your plants. And be prepared: You might be surprised at how much a mist such a small unit can generate!

But even though the Mistmate can produce a heavy mist, it doesn’t have the power to distribute the vapor over a large area. You’ll have the best results if you use this humidifier in a small growing room. 

At the lowest setting, you can get as many as 20 hours of runtime, so you can look forward to infrequent refills. But if you want a heavy mist, plan to refill your tank in about half that time.

Evaporative humidifiers generate water vapor by a fan blowing air through a thin, absorbent filter. This fan does make a bit extra noise, but it doesn’t rise much over the level of soothing white noise. 

One thing to be aware of: This humidifier doesn’t use a filter, which is nice from a convenience and care standpoint. But that also means that any minerals in your water can find their way around your room in the form of fine white dust. 

If you want to use tap water with this unit, demineralization tablets can be a helpful addition. Buying purified water is another option. 

  • Humidifier type: Evaporative
  • Best for small, medium or large room: Small room
  • Tank capacity: 1.9 liters
  • Approximate runtime: Up to 20 hours
  • Automatic shut-off: Yes
  • Product weight (empty tank): 3 pounds
  • Product dimensions: 8.5 inches long, 8.5 inches wide and 9.5 inches tall
  • Warranty: 2-year warranty

Pros

Cons

4. Vicks Warm Mist Humidifier

Here we have a warm mist humidifier from the classic Vicks brand, which has built a reputation for quality, long-lasting products. 

This warm mist humidifier for plants produces a heavy, slightly warm vapor that can help your tropical plants feel right at home.

A full tank produces up to 24 hours of mist, and you can choose between high and low-output modes. The high setting produces a dense mist that is likely to leave a small room with dripping walls, so this model is best for medium-sized growing rooms. 

One nice aspect of warm mist humidifiers is that they inhibit bacterial growth without needing a filter.

Warm mist humidifiers have an internal heater that warms the water to its natural evaporation point. Most bacteria can’t survive such a high temperature, and Vicks claims that this humidifier eliminates 95% of water-borne bacteria. 

As long as you keep up with regular maintenance, you shouldn’t have too much trouble cleaning the tank and outer layer. 

But keep in mind that the heating plate also requires frequent care. Minerals can build up quickly if you fill the tank with tap water, potentially reducing mist output or shortening the unit’s life. 

  • Humidifier type: Warm mist
  • Best for small, medium or large room: Medium rooms
  • Tank capacity: 3.78 liters
  • Approximate runtime: 24 hours
  • Automatic shut-off: Yes
  • Product weight (empty tank): 4.75 pounds
  • Product dimensions: 12 inches long, 7.88 inches wide and 14.25 inches tall
  • Warranty: 3-year warranty

Pros

Cons

5. Everlasting Comfort Cool Mist Humidifier

If your houseplants live in a large, open area, you know how hard it can be to achieve the ideal relative humidity. This humidifier may be the answer to your problems. 

This humidifier makes good use of its 6-liter tank to generate up to 270 mL of water vapor per hour, which is enough to increase humidity in spaces up to 500 square feet. 

But you’re not limited to just running on the highest mist setting. The rotating dial on the front panel is incredibly user-friendly, so setting an ideal humidity level is a quick task.

The mist sprays from the outlet nozzle in two streams, and you can rotate the nozzle to direct the mist where you need it. And even though this model has the highest mist output capability of any options on our list, it also has the longest runtime, lasting up to 50 hours between refills. 

One gripe is the opaque plastic that keeps you from checking your water level at a glance. There is a water level indicator on one side panel, but it’s quite small and can be hard to see, especially from a distance. 

  • Humidifier type: Ultrasonic
  • Best for small, medium or large room: Large rooms
  • Tank capacity: 6 liters
  • Approximate runtime: Up to 50 hours
  • Automatic shut-off: Yes
  • Product weight (empty tank): 4.05 pounds
  • Product dimensions: 11 inches long, 7 inches wide and 13 inches tall
  • Warranty: 2-year replacement warranty

Pros

Cons

6. Hupro Cool Mist Ultrasonic Humidifier with Humidistat

Humidifiers have been around for a long time, but this one from Hupro gets a high-tech upgrade! 

The flat front panel contains six control buttons:

  • Power on/off
  • Timer
  • Humidity level
  • Mist output
  • Night mode
  • Warm/cool mist setting

You also get a handy remote control with the same six functions, so you can adjust your settings from across the room. 

One of the nicest features here is the humidity level setting and display screen, which is also called a humidistat. This feature lets you choose a target humidity level rather than having to play around with finding your ideal setting.

Especially if you’ve got plants that prefer very high relative humidity, a humidistat can help you achieve the right level. And you also have the option to turn on the internal heater for warm mist, perfect for those heat-loving tropical natives!

Another convenient feature is the top-fill tank. Instead of detaching the tank and carrying it to the sink, you bring the water to your humidifier and fill it on the spot. 

Just take off the tank cover, pour the water in, replace the cover and you’re good to go! 

Besides being easier and faster to refill, a top-fill tank also cuts down on spills and potential water damage if you have your humidifier on a wooden surface. Also, the wide-open tank has plenty of space to reach your hand inside, making it easy to keep clean. 

This humidifier has plenty of helpful tech and design features. But convenience comes at a cost, and you’re looking at a higher price tag. 

  • Humidifier type: Ultrasonic
  • Best for small, medium or large room: Adjustable output is suitable for any size room
  • Tank capacity: 6 liters
  • Approximate runtime: Up to 40 hours
  • Automatic shut-off: Yes
  • Product weight (empty tank): 6.07 pounds
  • Product dimensions: 14.06 inches long, 12.8 inches wide and 9.69 inches tall
  • Warranty: 1-year warranty

Pros

Cons

7. Homasy Cool Mist Humidifier

This little humidifier has a simple design that gets the job done without all the extra bells and whistles. It’s also an excellent pick if you’re on a budget and have a small to medium-sized growing area. 

There are two mist level options to choose from, controlled by a simple button on the front panel. And if you want a little extra soothing ambiance, the base also lights up in several colors. 

At the low setting, this humidifier generates about 80 mL of mist per hour and runs for up to 30 hours. 

On the high setting, you’ll get 180 mL per hour with about 12 hours of runtime between refills.

That’s a fairly heavy mist, and there have been a few people who’ve reported issues with water pooling on the humidifier lid on the high setting. 

One really nice feature is the top-fill tank. Just lift the lid off, refill, replace the lid and get on with your day. Also, the wide-open tank is easy to reach inside for a thorough cleaning. 

The only issue to point out is that the lid does not lock or snap into place. If you happen to bump into your humidifier, the lid may get jarred loose. 

  • Humidifier type: Ultrasonic
  • Best for small, medium or large room: Both small and medium rooms
  • Tank capacity: 2.5 liters
  • Approximate runtime: Up to 30 hours on low setting, up to 12 hours on high setting
  • Automatic shut-off: Yes
  • Product weight (empty tank): 2.9 pounds
  • Product dimensions: 7.28 inches long, 7.28 wide and 11.61 inches tall
  • Warranty: 1-year warranty with a 2-year option available upon registering through the Homasy website

Pros

Cons

What is Humidity and Why Is it Important?

In essence, humidity is the amount of moisture suspended in the air. This moisture takes the form of water vapor, which are tiny particles of water. 

The National Weather Service breaks humidity into two forms:

Absolute humidity is the gram-weight of water contained in a cubic meter of air at a given temperature. You’ll see absolute humidity expressed as a weight/volume comparison. 

Relative humidity is the amount of water currently in the air vs how much the air is capable of holding. This is the percentage measurement we’re more familiar with: For example, your home may have 40% humidity.

Temperature plays a huge part in relative humidity. Warm air has a greater capacity to hold water in vapor form. In colder air, water starts to condense into droplets instead of remaining in vapor particles. 

But why does humidity matter?

Think of the most fertile, lush places on Earth. Rainforests and other warm, rainy areas probably spring to mind. These regions tend to be along the equator and have a consistently high temperature, allowing for greater relative humidity. 

But warmth alone can’t create high humidity. Deserts are certainly hot, but the lack of rain or any other bodies of water makes extremely low relative humidity. 

In short, a combination of moisture and a warm temperature translates to higher amounts of water in the environment.

And more moisture typically leads to better plant growth.

What Makes Certain Plants Need More Humidity?

Some plants are easy-going and don’t mind low relative humidity. 

On the other hand, many plant species just won’t thrive unless you provide that extra water vapor. 

Here are some of the most common ones:

Graphic showing humidity-loving houseplants

What do all these plants have in common? They’re all native to tropical regions.

Plants that grow naturally in warm, moist habitats don’t just take in water through their roots; they also absorb it through their leaves. 

A humidifier can help a lot in mimicking a tropical plant’s native environment, giving you the best chances for a healthy, happy houseplant. 

Even if it’s not on the list above, almost any houseplant that originates from a warm, moist climate will probably benefit from a humidifier.

Make sure to research your specific plant’s background if you have any questions. 

RELATED: Stop by our article on Philodendron Splendid to learn more about a rare, beautiful tropical hybrid plant. 

Types of Humidifiers

There are three basic types of humidifiers: 

  1. Warm mist
  2. Evaporative 
  3. Ultrasonic

Each type operates on a slightly different moisture-generating principle, so let’s look at their individual features along with pros and cons.

Warm Mist

These humidifiers produce mist with an internal heating element that brings the water in the tank up to a boil, thereby creating steam.

Remember what we said earlier about warm air having a greater capacity for relative humidity? If you’re looking for maximum output, a warm mist model delivers. 

All humidifiers run on electricity, so you may notice a small increase in your utility bills with any model you choose. But since warm mist models use a heating element, they tend to run up your electricity charges the most. 

Pros of warm mist:

  • Boiling water can cut down on microorganism growth (you still need to clean your humidifier regularly, though!)
  • Excellent humidity output

Cons of warm mist:

  • Expensive to run
  • Boiling water could be a hazard

Evaporative

These are the traditional cool mist humidifiers you probably had growing up. 

Evaporative models essentially hasten the natural evaporation process. A wick made from thin, highly-absorbent material draws water up from the reservoir, and a fan blows air through the wick. This generates water vapor that exits through the humidifier’s nozzle and into the room.

One nice thing about most evaporative humidifiers is that they use a filter to remove some of the chemicals and microbes that may be in tap water. However, that also means you’ll need to change or clean your filter. 

Also, the fan creates a steady hum of noise. While the noise usually isn’t obtrusive, it’s likely to be noticeable.

Pros of evaporative humidifiers:

  • No risk of boiling water
  • Filter traps some contaminants

Cons of evaporative humidifiers:

  • Can be a little noisy
  • Tend to be larger/bulkier
  • Replacement filters are an extra expense

Ultrasonic

Ultrasonic humidifiers are the newest on the scene, but they’ve quickly gained popularity and are widely available. 

These humidifiers produce water vapor through high-frequency vibrations. The vibrations cause the water molecules to rapidly bump into one another and break free of their liquid form, thereby becoming water vapor. 

Some ultrasonic models have the option to use a heater to raise the mist temperature, but they aren’t true warm-mist humidifiers. 

Ultrasonic models have the benefits of quiet operation and small size. Although they don’t use an actual microbial filter, some ultrasonic humidifiers may include a cartridge insert that traps minerals in tap water.

However, most cartridges can’t trap all minerals, and you may notice a build-up of fine dust on your humidifier. Also, ultrasonic models can be more prone to mold growth since there’s no heat or filter to stand in the way. 

Pros of ultrasonic humidifiers:

  • Super-quiet operation
  • Tend to consume less electricity than warm mist or evaporative models
  • No filters to change or hot water to worry about

Cons of ultrasonic humidifiers:

  • Need frequent cleaning to prevent microbial growth
  • Can produce mineral dust
  • Replacement cartridges are an additional cost

What to Look For in the Best Plant Humidifiers

So all these humidifiers we’ve looked at are impressive options, but which one is right for you? 

Here’s a breakdown of various features, and how to determine which ones you actually need:

Appropriate Output for Your Room Size

The size of your growing area is the fastest way to narrow your humidifier search. 

Since a room that seems small to one person may be large to another, use these measurements as rough guidelines:

  • Small rooms: Up to about 200 square feet
  • Medium rooms: 200 to 400 square feet
  • Large rooms: More than 400 square feet

Small rooms are the biggest concern here. Too much humidity can result in unsightly and potentially dangerous mold growth in walls or other household structures. 

Aim to keep your home’s relative humidity below 60%, and place your humidifier at least a few feet away from any walls or woodwork.

Larger rooms are a little easier to work with. Just be sure to place your humidifier near your plant to concentrate the moisture where your plant needs it. 

Automatic Shut-Off

Running your humidifier with no water in the tank is both an electrical safety hazard and an unnecessary drain on power. 

To keep this from happening, most humidifiers have an automatic shut-off feature. A sensor in the reservoir tank monitors water levels and cuts off power when the level drops too low. 

Noise

Do you have memories of a clunky, noisy humidifier from your childhood? A constant dripping sound may be coming to mind here.

If you do, don’t worry! Modern humidifier designs have come a long way over the last couple of decades, and many models are whisper-quiet. 

Evaporative models are the most old-school, and their internal mist-producing fan creates the greatest noise level. However, even this shouldn’t rise to the level of truly annoying for most people. 

If quiet operation is high on your priority list, ultrasonic models are your best bet. 

Total Runtime

Simply put: The longer the runtime, the less often you’ll need to refill your humidifier. 

And that’s always a good thing! But especially if you’re away from home for several hours each day, long runtime can also mean the difference between reliable function and dried-out plants. 

For the most part, a larger tank will usually result in longer runtime.

But that’s not always the case. Some humidifiers have an exceptionally efficient design, so even a small tank can last for over 24 hours. 

Also, take the mist output level into consideration. High-output models will always run through water faster, so even a large tank can drain pretty quickly. 

So don’t make the mistake of assuming that tank size automatically correlates to runtime.

Instead, be sure to pay attention to the manufacturer’s stated runtime for each model and be prepared to go through a little trial and error of your own. 

Warranty

Even though a humidifier isn’t a huge expense, it’s still nice to know what you can expect from the manufacturer if you run into a problem. 

Under normal use conditions, a 1-year or 2-year warranty is the most common, with a few manufacturers offering even longer warranty periods. 

Easy to Clean

Since a humidifier is a damp, mold-prone item, you’ll have to maintain it regularly for optimal performance and safety. 

Look for a model that’s easy to take apart. A simple design can help eliminate the temptation to leave your half-filled tank sitting idle, growing a film of mold or mineral build-up. 

Consult the manufacturer’s instructions for specific details on cleaning your humidifier. This article from Good Housekeeping has lots of helpful tips for generalized cleaning and sanitization.

Here’s a breakdown of basic regular care:

Make it a weekly habit to wipe down the reservoir tank with a mild, natural antibacterial and anti-fungal substance. Plain white vinegar is both effective and inexpensive, so it’s a great choice here. 

You can also partially fill the tank with vinegar and let it sit for a while. This will help break up mineral deposits that may be left over from tap water. 

After cleaning, rinse and air-dry all your parts, then reassemble and get back to work!

Easy to Transport

This may not be a concern for every houseplant parent out there. But it’s worth considering if you:

  • Move your plants from one room to another seasonally.
  • Only use your humidifier for part of the day and then want it out of the way.
  • Want to give a moisture boost to plants living in various areas of your home.

If you plan to move your humidifier, a smaller model with a compact tank is probably your best bet.

The Honeywell HUL520B Mistmate we looked at in spot #3 also has a built-in carrying handle, so it’s a great choice if you’re looking for the best in portability. 

Humidistat Display

A humidistat is a display screen that reads the current relative humidity. This is a helpful feature to have, especially if you’re working with a small growing space that could easily grow overly damp. 

Humidistats usually take the form of a digital LCD display, so they’re easy to see from across the room. 

Alternatives to Electric Humidifiers

Do you have just one plant that prefers humid conditions or you’d like to use an electricity-free method?

If so, a humidifier isn’t your only option for adding extra moisture to the air:

Misting. A good old-fashioned spray bottle is a great alternative for small-scale humidification. 

Give your plants just enough mist to produce tiny droplets on the surface of the leaves, like the photo shows:

A woman mists a houseplant for cleaning and humidity

Also, make sure to lightly spray the underside of the leaves as well. 

How often should you mist your plants? That depends on their specific moisture needs. Plants that come from very humid climates may like a daily misting, while those from slightly less-moist habitats do better with once- or twice-weekly misting. 

You may need to experiment a bit to find the perfect misting schedule. Whatever frequency you settle on, make sure to do it in the morning so your plant has all day to absorb the moisture before darkness falls. 

Build a humidity tray. Harness the natural evaporation process by settings a tray of water near or underneath your plant. 

This method enriches only the air immediately around your plant, so it can be a great strategy for small growing spaces. 

Also, adding a layer of small pebbles to your humidity tray helps keep your evaporation at an even pace. It looks pretty, too! 

Add plants that produce humidity naturally. Some plants release humidity of their own making, so they could be great companions for moisture-craving plants. 

A few moisture-generating plants include:

  • Dracaena marginata
  • Spider plant
  • Boston fern
  • Rubber plant
  • Jade

To take full advantage of this method, group your plants together thoughtfully.

Typically, the larger the plant leaves are, the more moisture they release. So placing shorter plants near taller ones lets the smaller leaves easily absorb the extra humidity. 

Just be sure to avoid overcrowding. Keep several inches of space between plants for good airflow. 

Frequently Asked Questions about Plant Humidifiers

It’s possible. Without the proper care and cleaning, your humidifier tank and pieces could harbor mold and fungus, and these organisms can then enter your home’s air through the mist spray. 

No. As natives of dry, arid environments, succulents take all their water in through their deep roots and store it away in their thick leaves. 

Aim for about 3 to 6 feet of space between your plants and the humidifier. This allows the water vapor to stay suspended in the air rather than settling immediately on your plant’s leaves.

Only if your plants live in a very small space. Diffusers just don’t have the output to be effective over a moderate or large area. 

It might be a little surprising, but the water vapor temperature doesn’t really make any difference.

Since warm has a greater capacity to hold moisture, warm mist models may produce greater humidity output. But your plant won’t notice if you use a cool mist or a warm mist! 

Run your humidifier for at least 4 to 6 hours every day during the morning or afternoon.

But don’t use your humidifier during the evening or overnight: Evaporation slows during these cooler hours, and you could end up with overly damp plants or walls. 

Every day! It’s totally fine if you miss a day here and there, but aim to give your plants the humidity they need daily. 

Most plants tolerate high relative humidity with no problems. 

However, most succulents and other plants native to dry environments are the exception. In high ambient humidity, your succulent could start to grow mold or develop mushy, saturated leaves. 

Final Thoughts

There’s no shortage of good options when it comes to the best plant humidifiers!

As a summary, these are the main points to keep in mind when shopping for your humidifier:

  • The size of your growing area
  • The level of moisture your plants need
  • How often you want to refill your tank
  • Your budget

Think about your needs and check out the specifics of each humidifier model. Then pick one with confidence and look forward to happy, thriving houseplants!

Do you have any more questions about plant humidifiers? Or do you have any tips you want to share? 

We’d love to hear them in the comments!

If you found this post helpful, we encourage you to share it on social media! 

Share
  •  
  • 3
  •  
  •  
  •  
  •  
    3
    Shares

Leave a Comment

Your email address will not be published. Required fields are marked *

SeedsandSpades is a proud sponsor of Lifewater.org. 

Child drinking clean water from a well

Please note that 10% of ALL earnings from this site will go to support Lifewater.org.
Visit our sponsorship page for more information.

Popular Posts

Plan for success!

Sign up to get your FREE Spring Gardening Checklist printable!

Thank You!

Please check your e-mail to confirm your subscription.

Thank You!

Please check your e-mail to receive your gift!

Free Spring Garden Checklist

Organize your outdoor tasks and check them off one at a time.

We respect your privacy. Unsubscribe at anytime.