To grow orchids successfully, there are a few environmental conditions to stay on top of. Light and temperature are undoubtedly important, but one often overlooked aspect that can impact growth (and, more importantly, orchid flowering) is humidity.
If your home has average to high humidity levels throughout the year, your orchids shouldn’t struggle. Even if your humidity is on the lower end, tougher species like Phalaenopsis and Cattleya usually don’t mind.
But if you notice shriveled leaves or a lack of flowers in dry indoor conditions, it’s time to take steps to improve your humidity levels and meet your orchid’s needs.
Orchid Humidity Requirements
Higher humidity levels are a consistent feature in their diverse natural habitats.
No matter which type of orchid you’re dealing with, you can be sure it prefers higher humidity over dry air. While there are desert-dwelling species, they are not the predominant types sold for at-home care.
In their varied native environments, higher humidity levels remain a mostly consistent characteristic. They may not last all year, but even those in the driest environments experience essential periods of higher humidity that help them thrive and flower.
The ideal humidity range for most orchids is between 50%-70%. Some are fussier than others, only growing to their full potential in the higher end of that range. Others are better at adapting to lower levels, remaining relatively happy in around 40% humidity.
While humidity is important for growth, it’s not a condition most need to fuss over.
The humidity inside our homes is generally high enough for most species and can be supplemented by regular watering. Even states with the lowest average humidity, like Arizona at around 50%, have enough moisture in the air to keep the more resilient orchids alive.
But there are some scenarios in which monitoring and improving humidity is essential:
- Your indoor air is excessively dry (below 30%), inhibiting growth and flowering.
- Your summer conditions are humid, but indoor heating dries out the air inside your home over the winter months.
- You’re growing a fussier orchid like a Bulbophyllum that doesn’t adapt well to lower humidity levels.
- You want to encourage better flowering that lasts as long as possible.
In these cases, take a look at the few ways you can increase humidity around your orchids.
Ways To Increase Humidity Around Orchids
There are several ways to increase humidity around your plants, with varying rates of success. If you’re only looking for minor improvement, choose one of the easier methods that improves humidity slightly. If your humidity is very low, you’ll need to consider more intensive measures if you want to grow orchids long-term.
Choose Location Carefully
Set up humidity sensors in different rooms to monitor trends and changes.
The easiest way to raise humidity without maintenance is to choose a spot in your home with naturally higher humidity. Typically, these are rooms with water sources like kitchens or bathrooms, but it differs depending on your home.
I have a few humidity sensors set up in different rooms to monitor any trends and changes throughout the day. The difference between my upstairs and downstairs humidity can often differ by as much as 10%. I keep fussier plants in the highest humidity areas and move more tolerant plants to lower humidity spaces to make the most of the available space.
If a slight boost is all you need, choosing the right room could be the answer. Just make sure you can still meet all your orchid’s other needs in this spot, particularly when it comes to light, so you’re not sacrificing one improvement for another.
Group With Other Plants
Be aware that limited airflow between packed plants can create conditions for fungal growth.
Pairing your orchids with other houseplants that require frequent watering can also boost humidity, benefiting all the plants in the group.
This works particularly well with indoor ferns that appreciate consistent moisture. As leaves transpire and water evaporates from the soil, it will raise the humidity around all the plants slightly, creating a little micro-environment inside your home.
One risk you take when choosing this method is the proliferation of disease. Limited airflow between plants packed tightly together creates the perfect conditions for fungal growth, spreading quickly from one plant to the next.
Ensure there is enough space around each of the plants to remove any stuffy pockets and stop the leaves from touching.
Use A Pebble Tray
This is a low-maintenance and safe technique when executed accurately.
A pebble tray is a simple way to improve humidity in a localized area around the base of a houseplant.
If you don’t want to group plants together, you can create a similar effect using a drip tray, a few pebbles, and some water:
- Fill the drip tray with pebbles and place the orchid container on top.
- Fill the tray with water, keeping the water line below the pot.
- The pebbles will keep the base of the container dry to prevent rot.
- As the water evaporates, humidity levels around the orchid will increase.
- Refill the water as it evaporates, ensuring it never touches the roots.
I have tested this method, and it does make some improvements to humidity levels, but only slightly. It’s unlikely to make a drastic difference if your plants are really struggling. But since it is relatively low maintenance and risk-free when done correctly, there’s also no harm in trying to see what impact it has.
Mist The Roots
Directly misting orchid leaves heightens the risk of disease and can result in unattractive foliage spots.
Misting is one of the recommendations I hear most often, especially when it comes to orchids. Gardeners mist their orchids not only to increase humidity but also as a water source for epiphytic species.
Unfortunately, this comes with a few downsides. Directly misting your orchid’s leaves increases the risk of disease and can lead to unsightly spots on the foliage. Its impact on humidity is also incredibly short-lived, meaning you’ll need to mist several times daily to have any consistent effects.
Despite these downsides, a few gardeners still swear by misting their orchids. I wouldn’t recommend it, but if you go this route, keep the spray away from the leaves and focus on the roots to avoid damage.
Use A Humidifier
Investing in a humidifier is worthwhile for the successful cultivation of orchids.
The final method is the most effective for dramatically improving humidity – using a humidifier. This is the best defense against dry air, replicating the jungle conditions orchids appreciate. They can be pricey, but they’re worth the investment for successfully growing orchids and a range of other tropical houseplants.
When using a humidifier, keeping the spout away from your orchid directly is best. Mist spraying directly onto the leaves can lead to fungal disease. Instead, use the humidifier to raise the humidity in the room generally, stopping any droplets from settling in the leaves and causing rot.
Managing Air Flow
As humidity rises, airflow becomes even more important.
While increasing humidity can be beneficial, it can also encourage disease if you don’t manage airflow correctly.
Orchids, particularly epiphytic species, need gentle air movement around the leaves and roots to stay healthy. The more you increase your humidity, the more important airflow becomes.
When using any of these measures, it’s best to counteract potential downsides with a fan. A ceiling or standing fan on its lowest setting is gentle enough and more reliable than an open window.
The fan shouldn’t be pointed directly at the orchid as this can dry out the roots, but rather in the general area to eliminate any stale air.
Final Thoughts
Humidity is an essential component of successful orchid growth. Most regions have enough humidity to keep tougher orchids happy, but if you need to boost your humidity, try one of these methods.
