I like plants a lot. I admire them when I hike and visit gardens, and I’m a bit envious of my friends who have a knack for growing gorgeous plants and flowers, whether indoors or out.
But when it comes to my own home, I’ve never been much of a plant person. The few times I’ve tried adding even the hardiest houseplant to my environment, I’ve never been able to keep it alive. So I figure it’s best for the plants if I steer clear.
But recent research has me rethinking my houseplant aversion. For one thing, having some greenery in your home can help ease anxiety and improve mood. They also increase the oxygen level in your home, which helps with energy and mental focus as well as better sleep.
Plus, researchers have found that houseplants can naturally clean the air you breathe. This was reinforced by a recent U.K. study that found potted houseplants can significantly contribute to reducing indoor air pollution in homes and offices…
Improve indoor air quality with houseplants
In the study, researchers exposed three types of houseplants to the common pollutant nitrogen dioxide. Gas heaters, stoves, fireplaces and water heaters can emit nitrogen dioxide gas that can irritate the respiratory tract and trigger asthma symptoms, as well as lead to severe respiratory infections and chronic lung disease.
After monitoring the plants, the researchers determined that in some conditions, they could reduce NO2 by as much as 20 percent.
The researchers chose three houseplants that are inexpensive, easy to maintain and commonly found in U.K. homes: peace lily (Spathiphyllum wallisii), corn plant (Dracaena fragrans) and fern arum (Zamioculcas zamiifolia). They’re also found in homes in the U.S.
Each plant was put by itself in a test chamber for an hour. The test chamber contained levels of NO2 comparable to those in the air of an office located next to a busy road.
According to the researchers’ calculations, all three types of plants were able to remove about half the NO2 in the chamber within the hour. Their performance wasn’t affected by whether their environment was light or dark or whether their soil was wet or dry.
“The plants we chose were all very different from each other, yet they all showed strikingly similar abilities to remove NO2 from the atmosphere,” says lead researcher Dr. Christian Pfrang of the University of Birmingham. “This is very different from the way indoor plants take up CO2 in our earlier work, which is strongly dependent on environmental factors such as nighttime or daytime, or soil water content.”
The researchers compared what results would be for a small office of about 15 cubic meters and a medium office of about 100 cubic meters. They found that adding five houseplants would reduce NO2 levels by about 20 percent in a poorly ventilated small office with high levels of air pollution. Adding five houseplants to the larger office only reduced NO2 by 3.5 percent, though adding more plants would likely increase the effect.
One thing the researchers couldn’t determine is exactly how the plants reduced the NO2.
“We don’t think the plants are using the same process as they do for CO2 uptake, in which the gas is absorbed through stomata — or tiny holes — in the leaves,” Pfrang says. “There was no indication, even during longer experiments, that our plants released the NO2 back into the atmosphere, so there is likely a biological process taking place also involving the soil the plant grows in — but we don’t yet know what that is.”
“Understanding the limits of what we can expect from plants helps us plan and advise on planting combinations that not only look good but also provide an important environmental service,” says Dr. Tijana Blanusa, principal horticultural scientist at the Royal Horticultural Society and one of the researchers involved in the study.
Plant care for those with a black thumb
If you’re a plant care beginner — or if, like me, you have a tendency to kill your plants — here are some tips to help you become a better plant parent.
First, check the light in the room where your plant will go. Is it direct or indirect? Is the light bright or dim? Once you figure that out, you’ll be able to choose the kind of plant that will thrive in that type of light. You wouldn’t want to put a dark-loving peace lily in direct sunlight, for instance.
Next, make sure your planter has a drainage hole to let excess water escape the soil. This will help keep the roots from rotting and your plant from drowning.
Speaking of drowning, go easy on the water. Plants die much more often from over-watering than under-watering. Before you water, test the soil with your fingertip. If it’s still moist, it’s not time to water yet.
Finally, don’t be afraid to move your plant to a slightly bigger home when they outgrow their first. The best time for repotting is in the spring, so make moving your plants to a new pot with fresh soil part of your spring-cleaning routine every year.
One thing to note: if you have pets or small children, you’ll want to choose your houseplants carefully. For instance, both peace lily and fern arum are toxic to both pets and children when ingested, and corn plant is toxic to pets but not humans. Check with an expert at the nursery where you’re acquiring your plants before bringing them home to your pets or kids.
You can look up any plant that you’re planning to purchase in the ASPCA’s searchable Toxic and Non-Toxic Plants List to make sure it’s safe for your pets.
Sources:
Common houseplants can improve air quality indoors — University of Birmingham
Potted plants can remove the pollutant nitrogen dioxide indoors — Air Quality, Atmosphere & Health
Health Benefits of Houseplants — WebMD
Surprising Health Benefits of Getting Fresh Air — Long Island Weight Loss Institute
Poisonous Houseplants: 10 Indoor Plants For Pet Owners And Parents To Avoid — Pistils Nursery
8 Things First-Time Plant Owners Should Know, According to Plant Whisperers — Glamour
Is Dracaena Plant Safe for Humans, Dogs, or Cats? — Ready to DIY