Houseplants 101: Humidity

Houseplants 101: Humidity

Certain houseplants need more humidity than we usually have in our homes. In fact, some can even exhibit health issues if they need more moisture in the air than they are getting.

Often, as concerned houseplant owners, we look for more obvious fixes (like watering or light) to address problems. We can then end up overcompensating with too much water or starving our plant of light, when the issue could be fixed with just a bit of increased humidity.

Plants that need high humidity

Ferns, carnivorous plants, nerve plants, prayer plants, philodendrons, monsteras, orchids, fiddle leaf figs, anthuriums, air plants, and most other tropical plants love high humidity!

How to Tell Your Relative Humidity?

You can invest in a hydrometer if you’d like to be able to test the relative humidity of your space.

Symptoms of Low Humidity

This Calathea ornata leaf is showing its dark maroon underside due to curling. It also has a brown tip. Both are signs of low humidity.

Low humidity can be a little difficult to diagnose because some symptoms can be similar to underwatering or too much light. Leaves can turn dry and brown at the tips or along the edges. (Tips usually indicate humidity issues, while underwatering is usually seen more on the sides.) Leaves or flowers can dry and shrivel up. Some plants may curl their leaves inward or down. If a new leaf unravels and looks misshapen, that might be because it formed during a time with too low humidity.

Symptoms of too High Humidity

Certain plants, like most cacti and succulents, prefer dry conditions. If they are kept in overly humid conditions for too long, you may notice issues with fungus that can lead to losing leaves or branches and eventually dying.  Similar symptoms could also be from overwatering.

Seasonal Differences

A typical home has about 40% to 60% relative humidity during the warmer seasons. Many houseplants are comfortable with this, though some may need some extra accommodation to be their happiest.

In winter, especially with the central heat on, the relative humidity of an average home often falls to 10% to 40%. Many plants will struggle with this and you may need to take some steps to raise it. Of course, most cacti and succulents won’t have an issue!

Humidity and Air Circulation

If you use any of the strategies below to raise humidity, please make sure that you also supply good air circulation. High humidity and low circulation is a recipe for potential fungus issues.

How to increase humidity?

One of the easiest ways to increase humidity is to locate plants in an area of your home that is naturally more humid. Examples might be in the bathroom or near the kitchen sink.

Grouping Plants

You could also think about grouping your humidity-loving plants together. As plants transpire, they increase the humidity around themselves. When they are grouped together, a small micro-climate of increased humidity occurs.

Humidity trays

Pebble trays filled with water under your plants are an easy way to increase the local humidity directly around a plant. Make sure that the pebbles are holding the bottom of the pot above the water, you don’t want to end up with oversaturated substrate (potting media.)

Humidifier

Investing in a humidifier might be the right choice if you’d like more control cover your humidity levels. Many come with the ability to set a humidity goal and will regulate the output of moisture to match it.

Fountains and Aquariums

A bubbly, moving fountain (as pictured at the top of this post) or open-air aquarium are also options. Aquariums can be a source of aqua-scaping inspiration as well. (Added bonus: aquarium water is a great gentle fertilizer for plants!)

Terrariums and Cloches

A fun way to increase humidity is to create a humid environment inside a transparent enclosure or dome. You can repurpose any glass or plastic container for this. Keep in mind that if your vessel is mostly closed, you should be careful to open it occasionally so that your plants get enough air circulation.

What About Misting?

Misting is often suggested as a way to increase humidity, but it doesn’t have a significant effect overall; it only increases humidity for a matter of minutes. Plants will absorb the water drops that land on their leaves, but misting can also cause water to stay on the leaves for too long, potentially leading to fungal issues (especially in cooler temperatures.)





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