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Houseplants from tropical rainforests grown in dryer climates need humidity support to survive and thrive. Fortunately, several humidifier options offer hot or cold mist, varying tank sizes, automation, low noise levels, and the ability to control remotely.
Humidity as a Plant Health Factor
Atmospheric humidity is expressed as the percentage of moisture in the air. This is important to plants as it impacts their transpiration rates and helps manage plant temperatures.
A humidifier attached to heating or ventilating systems can help manage humidity levels. Standalone humidifier units allow you to manage an environment dedicated to tropical plants.
Many articles suggest misting as a means of raising the humidity. While this may work, it is ill-advised as it increases the potential for pathogen spreading, increasing the risks of plant diseases.
Plant Transpiration
Through transpiration, plants move water and nutrients from their roots to their stems and leaves. As the water approaches the leaves, it is released into the atmosphere through tiny pores (stomata).
Interestingly, this process does not occur in succulent species that have evolved to keep their stomata closed during hot days and only breathe at night, limiting moisture loss.
High humidity slows transpiration and, in effect, reduces nutrient flow via the xylem. Epiphytes, plants that grow on trees in a non-parasitic relationship, have limited access to soil nutrition and need to keep what they have.
High humidity levels make this possible as low foliage moisture loss reduces xylem activity (upward flow of nutrients from the roots to leaves) while maintaining phloem activity – the downward movement of photosynthesis-produced sugars to the roots.
The Effect of Air Conditioners on Houseplant Humidity
In the winter, heating systems distribute dry, warm air throughout the home, while air conditioning systems do the same in the summer. Both conditions frequently produce an atmosphere with less than 10% humidity.
Ten percent is way lower than the relative humidity levels seen in the native environments of most tropical plants, which range from 70% to 90%. Additionally, in nature, plants are exposed to more air movement.
Closed vents for heating or cooling increase a plant’s need to transpire, and the lack of humidity causes many plants to develop leaf blotches or brown tips.
Factors to Consider When Choosing a Humidifier
Other than intangible factors such as aesthetics, you will also need to consider room size, plant needs, ventilation, and usage costs – both time and money.
Balancing Humidity and Airflow
High humidity levels (more than 70%) without ventilation are ideal for fungi development.
Wind can alter transpiration rates by removing the boundary layer, that even layer of water vapor hugging the surface of leaves.
Choosing a Humidifier Based on Room Size
Finding a humidifier with a moisture output that matches your room’s size is essential. If your humidifier’s production is less than what the size of your space requires, you might not achieve optimal moisture dispersion.
It’s also helpful to consider where you’ll locate your humidifier. It’s best to place your humidifier at least 6 feet away from your plants, especially if your unit has a fan because the direct airflow can contribute to your plants’ moisture loss.
Humidifiers are not all created equal. For example, a little kitchen herb garden might benefit significantly from using a smaller humidifier, but a vast grow room would not. However, strong humidifiers will leave small spaces soaked, and they might have a more appropriate lower setting.
For optimal results, use a large, powerful humidifier in a room of at least 500 square feet. Choose a medium or small humidifier for smaller rooms. Consider a sizable humidifier with a range of humidity level settings if you want something adaptable for different spaces.
Choosing a Humidifier Based on Plant Needs
Low humidity may be indicated by browning and drying at the tips or margins of leaves. One solution is to choose plants that require high humidity levels.
If your environment’s air is dry, consider using plants that require a lower humidity level. Succulents, the cast iron plant (Aspidistra), Chinese evergreens (Aglaonema), and Dracaenas are a few examples of plants that thrive in lower humidity levels.
Plants that thrive at higher humidity levels are your aroids (Araceae) (Philodendron, Monstera, Pothos, Spathiphyllum, etc.), begonias, prayer plant, and Calathea species.
Installing a humidifier on your HVAC system can increase the humidity throughout your house. If the air in your home is arid during the winter, this could also benefit you. Alternately, use a portable humidifier to control the humidity in specific rooms.
Another choice is to put plants in the kitchen or bathroom, typically more humid than in other parts of the house. Avoid planting plants near radiators, heat vents, exterior doors, and air ducts.
Plant misting is not a practical approach. To affect the levels of absolute air humidity, you would need to spritz plants frequently—every few minutes, at least. Additionally, plants are more vulnerable to leaf spot infections when leaves are constantly damp.
If you mistreat your plants, do so in the morning so their leaves will dry by evening. Cool, moist leaf surfaces at night provide the perfect conditions for disease infection.
Choosing a Humidifier Based on Setting Options
To avoid releasing too much or too little moisture, your humidifier’s moisture output should correspond to the room’s temperature.
Because of this, humidifiers are made with mist output settings that may be adjusted based on the surrounding air quality. Most humidifiers have two settings, usually low and high.
Three-speed devices are available if you need more control over the mist output.
Some models record relative humidity percentages and respond appropriately according to your settings. Please take a look at our suggestions further down.
Choosing a Humidifier Based on Tank Capacity
The amount of time a humidifier can operate without your input is directly inversely proportional to the size of the water tank.
Larger tanks can run for a couple of days without refilling. Depending on your needs, you can choose compact, stylish units perfect for small spaces with low moisture requirements.
Choosing a Plant Humidifier Based on Noise Level
All humidifiers are not created equal when considering noise levels. You might want a low-noise unit if you spend much time in or close to your grow area. The fan that pulls air across the wicking component in evaporative humidifiers tends to be noisier than ultrasonic types.
Choosing a Plant Humidifier Based on Setup and Maintenance
Regular maintenance can keep your humidifier operating effectively and free of the germs and mold that may develop in the tank if it isn’t cleaned correctly.
If not controlled, distributed mold in the mist can cause allergies and respiratory conditions. Cleaning or changing the filter will ensure the humidifier’s moisture is free of allergens.
Unwanted mold and mineral accumulation can be avoided by rinsing the tank with a diluted hydrogen peroxide solution (about a 0.6% solution).
Depending on your water, Humidifier filters should be changed every two to three months. Filtered water helps extend the filter’s lifespan and the time between changes.
Read the instructions to find out what you need to do and when. If you want a low-maintenance solution, filterless units are also available.
Plant Humidifier Options
Humidifiers turn water into fine steam or mist to enhance the amount of moisture in the air around you. It’s comparable to how your home’s air gets steamy when you run a hot shower.
Even though you may be familiar with an ordinary humidifier, you might be curious how it differs from a humidifier designed for plants.
Although a home-use humidifier’s functions may be identical across models, how much moisture is released can vary. The main difference is the method used to generate steam.
Below are descriptions and examples of the two humidifier types.
Ultrasonic Humidifiers
Ultrasonic humidifiers use high-frequency (ultrasonic) vibration to speed up water evaporation. Fog is generated by ultrasonic vibrations, creating extra-fine droplets.
In general, ultrasonic humidifiers are more expensive than evaporative ones but quieter and don’t require changing filters. They also reduce the likelihood of burn injuries because the ultrasonic conversion of water to mist does not need heating.
When buying an ultrasonic humidifier, always look at the drop size it can produce. Droplets below 5 microns will thoroughly humidify your room without creating wet patches.
Simplified Gardening Suggested Ultrasonic Humidifier
LEVOIT LV600HH Humidifiers for Large Room, 6L Warm and Cool Mist Top Fill Air Vaporizer, Smart App & Voice Control, Quickly Humidify up to 753 sq. ft, Quiet Operation, Timer
Founded in 2017, Levoit is a woman-owned company in Anaheim, California. Their vision is to create products centered around you rather than only centered around the home.
Amazon Reviews LEVOIT LV600HH
89% approval from 13,354 buyers (4- & 5-Star Ratings)
With the APP control, the patent warm and cool mist offers four times faster humidification than similar humidifiers. An ideal way to maintain the humidity levels needed by your plants.
The 1.59-gallon (6 liters) tank will last a staggering fifty hours, humidifying an area of up to 753 square feet (70m2) in its worry-free auto mode for larger rooms – keeping your plants vibrantly healthy.
The VeSync App allows you to monitor your plant’s humidity remotely, create schedules and timers, and connect to a third-party intelligent voice assistant to free your hands. No matter where you are, you can tell Siri (or google) to up your plant’s humidity.
One of the possible challenges of humidifiers is topping them up without spilling. The top-fill design makes refills and cleaning quick and straightforward – no need to flip anything upside down.
With Sensor, the humidifier can automatically turn on or off based on the setting. You can maintain the room humidity at a healthy and constant level, on the unit or remotely.
The plant node offers comprehensive plant-care programs, including scanning recognition, professional encyclopedias, and specialized custom plant humidity level management.
LEVOIT LV600HH Specifications
| Brand | LEVOIT |
| Special Feature | Warm and cool mist humidifier |
| Color | White |
| Capacity | 1.59 gallons (6 l) |
| Floor Area | 753 Square Feet (70m2) |
| Runtime | 50 hours |
| Item Weight | 6 Pounds (2.72 kg) |
| Model Name | Humidifiers for Bedroom Large Room |
| Material | BPA-free, suitable for babies and adults |
| Product Dimensions | 7.7″D x 11.6″W x 11.3″H 20cm D x 29.5cm W x 28.7cm H |
| Included Components | 1 x Smart Ultrasonic Humidifier 1 x Cleaning Brush 3 x Aroma Pads (1 pre-installed) 3 x Absorption Pads (1 pre-installed) 2 x Water Filter Sponge (1 pre-installed) 1 x User Manual 1 x Quick Start Guide |
| Voltage | 240 Volts |
| Wattage | 280 watts |
| Power Source | AC |
| Control Method | App |
Evaporative Humidifiers
Evaporative humidifiers draw water over a wick with a fan to create mist utilizing airflow. Additionally, evaporative humidifiers have filters that must be changed regularly to stop mold formation and germs.
Despite being less expensive than humidifiers that use ultrasonic technology, these models can be noisy due to the fan that forces airflow to produce moisture.
The added advantage of the Evaporative System is that it circulates the humid air, an essential factor in plant health.
Simplified Gardening Suggested Evaporative Humidifier
Vornado Evap40 4-Gallon Evaporative Humidifier with Adjustable Humidistat and 3 Speeds
The Evap40 by Vornado offers deep-pitched blades that pull large volumes of dry air through two humidifying filters and then circulate the humidified air throughout the room using Vornado’s signature Vortex Action.
The unit has three-speed settings that effectively humidify a space of up to 1 000 square feet (82.9m2).
The 4-gallon (~15 l) capacity provides up to 24 hours when operated continuously on high, allowing for long, uninterrupted operation and fewer refills.
Using the humidistat dial, the control panel lets you select your fan speed (low/750 RPM, medium/1150 RPM, or high/1600 RPM) and your desired humidity level.
Two removable, spill-proof, leak-free tanks are simple to clean and refill.
Evap40 senses how much humidity and circulation is needed to maintain your ideal environment and automatically adjusts and is made in the USA and imported parts.
When choosing a Vornado humidifier, you invest in superior performance and design to deliver total satisfaction. If not, they’ll replace it for five years. Supported by a customer service team based in Andover, KS.
Built to meet U. S. voltage requirements. Certified, safety-tested, and warrantied for use only in the U.S.A
Frequently Asked Humidifier Questions
Here are some answers to questions you may have when using a humidifier to optimize the humidity levels for your plants, keeping them thriving every season.
When would I need a plant humidifier?
Humidifiers are essential when plants require higher humidity levels than your climate can offer. Rather than boosting relative humidity levels, AC and heating usage can cause the RH to drop to 10% – far below what most plants need.
What kind of humidifier is best for plants?
The best humidifier depends on several factors, including the size of the room, typical ambient conditions, and the amount and duration of humidity required by the plant species. I have the Levoit LV600HH above, and I’m super happy with it – as others use it.
Do humidifiers cause mold?
A humidifier’s water tank and filter can develop mold if it isn’t regularly cleaned and maintained. With the help of mist, the mold can be distributed into the air, causing various respiratory problems, from asthma to allergies.
What are the alternatives to an electric humidifier?
While pebble trays, plant clustering, and even misting are often suggested, these are generally inadequate at raising humidity levels by more than five percent.
Can I use a regular humidifier for my plants?
Absolutely! What is healthy for us is also beneficial for our plants! Numerous humidifiers are available now that offer a variety of technologies to fulfill your personal and professional humidity needs. A typical humidifier can also serve as a plant humidifier.
Summarizing What Humidifier Type Is Best for Plants
The best humidifiers manage relative humidity levels around plants without wetting the plant’s foliage. The examples above are great options.
