Mythbusting: Methods for Boosting Humidity

Keeping your plants happy includes making sure that they’re receiving the right levels of humidity. While there are some low humidity-loving plants, the majority of houseplants are happy with humidity levels of 40-60%. This is because humidity plays an important role in photosynthesis.

If you go to the spa and get a facial, your esthetician will use a steamer in order to increase humidity and open the pores on your face for the coming treatments. Well, some plants are no different, and when humidity levels are high their stomates open wider allowing them to take in more carbon dioxide. Plants need carbon dioxide in order to participate in photosynthesis, so making sure they have the right level of humidity is key.

That being said, not every plant wants or needs a trip to the spa in order to complete photosynthesis. Most are fine with 40% humidity, which is the average household humidity. It’s important to do research on your plant’s native habitat and understand how that impacts the humidity level that it wants.

A Snake plant that comes from a dry region is going to be happy in low humidity levels of 30%. On the other hand, a Calathea from a humid, rainy region is going to require humidity levels at or above 50% in order to thrive. The first thing you should do before trying to boost humidity for houseplants is to actually make sure that that’s something that your plant wants and needs.

When it comes to boosting humidity in your home for your plants, there are a few suggestions out there on how to do it. Since the right level of humidity is so important, it can be difficult to choose which method to employ.

Should you mist your plants, and if so- how often? And what about pebble trays, do they actually work? Should you invest money in a humidifier if there are lower-cost options that work like misting and pebble trays?

Never fear- Canopi is here to get to the root of what works and what doesn’t when boosting humidity in your home! We’re going to go method by method and debunk or confirm its humidity boosting effects.

Misting

Misting is far and away the most common advice you will come across on the internet for boosting humidity for your plants. But does it actually work to mist your houseplants?

The answer is yes and no. The idea here is that misting boosts the humidity because the water droplets on your plant’s leaves will evaporate into water vapor around your plant, boosting the surrounding air’s moisture content. The only problem is- that’s not how water vapor works.

When you mist your plant, it’s true that the droplets convert into water vapor- they just don’t stay localized around your plant. Through a process called diffusion, water vapor spreads through the entire room that your plant is located in. For this reason, it can’t really boost the humidity of the entire room by too much.

“But wait a minute!” You say, spray bottle in hand. “Nurseries and growers use misters to boost humidity!” Yes, that is true- but they are misting over the entire space in an environment with already very high humidity that allows that water vapor to stick around for a lot longer than our much drier homes.

Greenhouses typically have a humidity level of 80% or higher and use large-scale industrial misters to mimic tropical plants' native habitats. Most homes have an average humidity level of 40%, meaning that that drier air is not going to allow the water vapor from misting to hang out for very long.

“But wait again!” You say, now with a spray bottle in each hand and a crazed look in your eye. “What if I just increase my misting throughout the day? That has to make a difference!”

You’re right! In your average home, you would probably have to mist your plant every 15-20 minutes in order to make some kind of effect on moisture levels. But my question to you is: do you have this kind of time and if so, please tell me how because I am jealous. Besides, do you know what misting every 15-20 minutes sounds like? A humidifier.

“But I love misting my plants and they are doing so well!” You cry, falling to the ground with spray bottles by your side. I hear you, I totally get it, and I agree! You see, I am a giant hypocrite- I have a Pachira aquatica that I absolutely love to mist every other day.

Even though I am writing all of this about the ineffectiveness of misting to boost humidity, I cannot deny that my Pachira looks especially happy after being misted. And that’s because for most plants misting does absolutely no harm at all.

Some plants like epiphytes even crave a misting, but there are others like Begonia’s that will not appreciate their leaves getting wet. The key thing is to know your plant and the native environment it comes from. Misting doesn’t hurt most plants, and it boosts the time that you spend with them- which is good for you and your plant.

So, by all means, if it makes you and your plant happy: mist your plants. Just don’t do it if you are trying to solve a serious problem of low humidity.

Pebble Trays

Another common method to boost humidity that you will see roaming around blog posts and plant care articles is using a pebble tray. This method entails placing your plant on a tray filled with gravel or pebbles and water.

The idea here, again, is that the water in the tray will evaporate into water vapor and raise the humidity level around your plant. The pebbles are so you can leave your plant on the pebble tray for as long as it takes for the water to evaporate without letting its roots sit in water.

Does it work? Yes and no, but more so no. Just like we discussed with misting, the water will become water vapor but it won’t necessarily hang out around your plant. It will travel throughout the room that your plant is placed in during that same diffusion process.

“Where’s the data to support this claim?” You demand, with gravel coming out of your pockets and dripping from your hands. An Australian orchid enthusiast from the Orchid Societies Council of Victoria tested out the effectiveness of pebble trays and found that at most, pebble trays increased the humidity by 7%- and only at 1.5” above the pebble tray.

It’s important to note that that was also in the summertime when higher temperatures and warmer air meant more humidity was already available. When conducted in winter, dry air made that number dropped to 3% at 1.5” above the tray. Those kinds of numbers are just not enough to make any sort of difference for a plant.

Bathroom and Kitchen Placement

Another tip that you’ll find when perusing articles on how to boost humidity is to place your high-humidity-loving plants in the bathroom or kitchen. The idea here is that the steam from showering or cooking will help boost humidity for your plant. But does it work?

When you take a shower, you exit into a steamy bathroom. But the bathroom doesn’t stay steamy forever, and usually within a half hour to an hour your mirror is defogged. Likewise, when you cook over your stovetop, you may notice your kitchen windows steam up, but they are usually clear within the hour.

You would need to endlessly boil noodles or take multiple showers throughout the day in order for these placements to have any real effect on your plants. And while that sounds luxurious and delicious, it just isn’t realistic for most people.

That being said, these rooms can still be good placements for your plants that need high humidity. Just don’t rely on the placement alone to help them stay happy.

Humidifier

Many articles and blog posts will suggest purchasing a humidifier for plants and placing it near your plants in order to boost humidity. Humidifiers can be expensive, and you may be wondering if they are worth the price.

Well- it depends. If used correctly, humidifiers are wonderful for boosting humidity because they are machines designed to do just that. That being said, a humidifier will not boost the humidity of your room or home unless it is designed for the square footage of your room or home.

If you keep all of your high-humidity plants inside one room of your home, then you want to make sure that the humidifier that you buy is designed to achieve higher humidity levels in that square footage. It does no good to buy a small humidifier that only works up to 250 square feet and place it in your 600-square-foot living room. There will simply be too much space for the excess water vapor to be effective.

This is where the question of “is it worth it” gets tricky. If you keep your plants in one room that isn’t too large or you live in a studio apartment, then buying a humidifier can make sense.

But if you want to keep your high-humidity plants in your cavernous grand foyer or your open-concept living room/dining room then you will be spending a lot more money- either on multiple units or one mega-humidifier. Then again, if you have a cavernous grand foyer I expect you are reading this through your monocle and using $100 bills to blow your nose, so purchasing a large humidifier should be no issue.

Humidifiers can also be pricey when you think about the fact that you would need to run them for most of the day in order to effectively boost the humidity in your home for a long period of time. Otherwise, we are back to the shower/water boiling scenario. That’s a lot of energy use, so make sure a humidifier is actually something that you want to invest in.

Terrariums, Indoor Greenhouses, and Humidity Domes

There is a wide range of products out there designed to bring the greenhouse into your home. From using aquariums to store plants, to glass domes over plants- these methods are basically all trying to do the same thing: create a microclimate within the microclimate of your home. The idea here is to put your plants in a smaller space so that the air that needs to stay moist is reduced. So, how effective are they?

This method is the most effective way to boost humidity for your high-humidity-loving plants. It makes sense when you think about it. The number one issue with all of these other methods we’ve discussed is space: the final frontier of humidity.

The methods above aren’t effective because of the size of the space that water vapor has to travel in. Why would it want to hang out with your plants? It can go read your books on the shelf or go work out on your Peloton.

But if you reduce the space that your plants live in, then you can effectively reduce the size of the area where the moisture in the air has to travel. This way, you can effectively trap the water vapor so that it has to hang out with your plant because it has no choice- there’s nowhere else to go! That may seem sinister, but your high humidity-loving plants will thank you for this evil plot.