Have you ever noticed the air quality alerts on your phone? They warn us to stay indoors because the smog outdoors is so bad. If you’re living in a major city, you may see the pollution casting its cloud over your downtown skyline. We often forget to consider indoor pollution in our homes.
According to the Environmental Protection Agency (EPA) report, on average, Americans spend nearly 90 percent of their time indoors. The report also states that indoor concentrations of some pollutants are often 2 to 5 times higher than typical outdoor concentrations (1). A study from April 2020 states:
“According to the World Health Organization (WHO), indoor air pollution is responsible for the deaths of 3.8 million people annually.”
The harmful pollutants inside buildings include volatile organic compounds (VOCs), particulate matter, aerosols, biological pollutants, carbon monoxide, and more (2).
Clever marketing has led many to believe that harsh chemicals are necessary to maintain a clean and sterile environment. Since the pandemic, the world has become hyper-vigilant to disinfect every possible surface with powerful chemicals to kill all traces of bacteria or viruses.
There has to be a balance. An animal study published in 2012 found that an over-sterile environment contributed to health problems in mice, like asthma, ulcerative colitis, and lung inflammation (3). We must rethink how we clean and what we use to clean our homes. Are we releasing pollutants into our home’s air?
Toxic indoor air can contribute to allergy symptoms and spread colds and flu-type viruses. More severe consequences can occur from toxic indoor air, including asthma, hypersensitivity pneumonitis, and Legionnaires’ disease (4). Indoor air quality can either contribute to or relieve symptoms of multiple chemical sensitivity (MCS). While MCS is not considered an “illness” by the American Medical Academy, it is a collection of noteworthy symptoms. MCS is a real issue for many people, myself included (5). Some professionals refer to it as sick building syndrome, and its symptoms include:
- Burning eyes
- Breathing problems
- Cough
- Changes to heart rhythm
- Chest pain
- Confusion
- Congestion and other sinus trouble
- Diarrhea, bloating, and/or gas
- Digestive problems
- Dizziness
- Fatigue
- Headache
- Itching
- Memory problems
- Mood changes
- Muscle and joint pain
- Nausea
- Poor concentration
- Rash
- Sensitivity to light and noise
- Sleep issues
- Sneezing
- Sore throat
- Trouble concentrating
This is a long list of undesirable symptoms. Clearly, we should be cautious with the products we allow in our homes. So, what can we do to improve indoor air quality?
If you read our blog, Everything You Need to Know About Air Filters, you know a simple way to improve indoor air quality is to address ventilation. Consider investing in air purifiers, regularly changing air conditioning filters, and adding houseplants that remove these pollutants.
6 Houseplants That Filter the Air
I scoured the internet looking for the best houseplants to add aesthetics to your home while also helping to filter VOCs. I found two studies that pointed toward the following six houseplants (6,7):
Peace Lily (Spathiphyllum wallisii Regel)
Peace lilies are sturdy, easy-to-grow plants with glossy, dark green oval leaves that grow directly from the soil and narrow to a point. Peace lilies typically grow between 1 to 4 feet tall, with some reaching 6 feet. Periodically, peace lilies produce lightly fragrant white flowers that turn a pale green as they age (8).
How to properly care for a peace lily (9):
- Peace lilies are tropical plants that prefer warmer temperatures (above 60°F) and should be kept away from cold, drafty windows. These plants do well in temperatures upwards of 70°F.
- Humidity is vital for peace lilies to thrive. Place the peace lily pot on a tray of moistened gravel, then mist its leaves to increase humidity.
- Peace lilies are not heavy feeders, only needing occasional fertilization to encourage spring and summer growth. Fertilize every six weeks with a balanced houseplant fertilizer starting in late winter.
- Repotting every few years, in the spring, is most pleasing for the peace lily, as it will enjoy the revitalized soil.
- Peace lilies’ leaves tend to collect dust; gently wipe them down with a wet paper towel occasionally. Too much dust can inhibit photosynthesis.
According to my research, peace lilies are unsafe for pets and children to consume but are safe to smell and touch. I recommend keeping them out of reach of small children and pets who may chew on them.
Snake Plant (Sansevieria trifasciata Prain)
Snake plants are the most common houseplants recommended. Snake plants are evergreen, perennial plants with dense and long sword-like leaves. Snake plants have dark green leaves with light grayish-green cross-bands that grow up to 3 feet tall and 2.4 inches wide (10).
How to properly care for a snake plant (11):
- If possible, water from the bottom of the pot to encourage the roots to grow downward and help stabilize the thick, tall leaves.
- Snake plants tend to develop root rot. Refrain from watering too frequently, and let the soil dry out nearly entirely between waterings. Additionally, water the plant less often during the winter months than you would in spring and summer.
- The snake plant’s large, flat leaves tend to accumulate dust; use a damp cloth to wipe them down as needed.
- Divide and repot your snake plant in the spring, cutting out sections containing leaves and roots. Be sure to repot in a well-draining potting mix.
According to my research, snake plants are unsafe for pets and children to consume but are safe to smell and touch. I recommend keeping them out of reach of small children and pets who may chew on them. I keep my snake plant out of reach on a high shelf.
Weeping Fig (Ficus benjamina L.)
Weeping figs are among the most popular house trees. Weeping figs have a drooping/weeping form, with smooth, gray bark and bright green, large, oval, leathery leaves. Some varieties of weeping figs have grayish-green or yellow-colored leaves (12).
How to properly care for a weeping fig (13):
- The weeping fig’s native habitat is usually semi-shady but requires adequate light to thrive indoors. A bright room with a surplus of indirect sunlight and a little direct sun in the morning is ideal.
- Keep the weeping fig moist, but do not allow it to sit in water, or it will lose leaves and may develop root rot.
- Tropical plants like the weeping fig prefer high humidity. They do best with nighttime temperatures between 65ºF and 70ºF and daytime temperatures between 75ºF and 85ºF.
- Weeping figs are heavy feeder plants needing a lot of fertilizer throughout the growing season. Be sure to feed your weeping figs with slow-release pellets at the start of the growing season.
- If leaves begin to drop despite ideal living conditions, try supplementing a little magnesium and manganese.
According to my research, weeping figs are unsafe for pets and children to touch or consume but are safe to smell and touch. I recommend keeping them entirely out of reach of small children and pets.
Areca Palm (Chrysalidocarpus lutescens Wendl.)
Areca palms have smooth silverish-green trunks with large, divided, and arched feather-shaped leaves. Areca palms usually have about six to eight yellow-green leaves on a long stalk/stem that curves upward, creating a butterfly-like appearance (14).
How to properly care for an areca palm (15):
- Indoor areca palms do best with a well-draining, peat-based potting mix soaking up sunlight from windows facing south or west.
- Areca palms prefer moist soil but are sensitive to fluoridated water, so they use distilled water or collected rainwater. Additionally, these plants are susceptible to overwatering and cannot tolerate waterlogging or sitting in a water-saturated potting mix. Let the soil dry out nearly entirely between waterings to prevent the development of root rot.
- Areca palms do best in temperatures between 65ºF to 75ºF. Keep the leaves away from cold windows, air conditioners, and heat sources.
- These heavy feeder plants need a lot of fertilizer from spring to early fall with a liquid fertilizer. Be sure not to feed your areca palm during the late fall and winter when the plant is dormant.
- Areca palms are prone to the tips and leaves turning yellow or brown, known as leaf tip burn. Leaf tip burn is usually caused by chilled air, over or underwatering, poor soil conditions, or compacted roots. You can cut these pieces off and address potential causes.
Guiana Chestnut (Pachira Aquatica)
Guiana chestnuts are often called money tree bonsais due to legends of the plant bringing good fortune. Guiana chestnuts are grown indoors and outdoors. Outdoor trees can grow to 60 feet tall, while indoor trees typically grow between 6 to 8 feet tall. Guiana chestnuts have shiny, green, lance-shaped leaflets 5 to 10 inches long. They also have large, greenish to yellowish-white flowers and long cream-colored petals surrounding 200+ tightly-packed, red-tipped bushy stamens that create a shaving-brush-like appearance (16).
How to properly care for a Guiana chestnut (17):
- Indoor Guinana chestnuts should be placed in bright to medium indirect sunlight or fluorescent lighting for at least six hours daily.
- Guiana chestnuts appreciate mild temperatures and high humidity between 65 and 75ºF. To increase humidity for the plant, place it on top of a pebble tray filled with water and should not be placed near warm or cold drafts. You can mist the leaves regularly.
- Guiana chestnuts should have a proper drainage container and be regularly watered. To avoid overwatering, ensure the top inch of soil is dry before watering. Watering should be more frequent in the spring and summer than in the fall and winter.
- Fertilize your Guiana chestnut with a basic fertilizer blend diluted to half-strength. When the plant produces new leaves in the spring and summer, fertilize monthly. In the fall and winter months, fertilize bi-monthly.
- Pruning is important in caring for your Guiana chestnut, especially if you wish to control its size indoors. Regular pruning of the lower leaves also helps encourage new growth at the top of the plant.
According to my research, Guiana chestnuts are completely safe for pets and children.
Philippine Evergreen (Aglaonema Commutatum)
Philippine evergreens are herbaceous perennial shrubs that grow to 1.5 feet tall. Its erect and bushy appearance resembles a dumb cane (Dieffenbachia) but can be distinguished by its 5 to 8 lateral veins. Other characteristic features of a Philippine evergreen include 4 to 8-inch long dark green, lance-shaped leaves that grow from stems with silver-gray blotches appearing on upright stems. Although uncommon, Philippine evergreens may bloom in late summer or early fall with white flowers and a greenish-white spathe enclosing the flower. Following a bloom, you may notice red clusters of berries (18).
It has elliptic, dark green, lance-shaped leaves that reach 4 to 8 inches long and 2 to 3 inches wide. Attractive silver-gray blotches appear on upright stems. It blooms rarely as a houseplant in the late summer or early fall with a white spadix and greenish-white spathe. Red clusters of berries follow the blooms.
How to properly care for a Philippine evergreen (19):
- Darker varieties of Philippine evergreens can grow in near-shade, while the lighter varieties require a bit more bright light. No matter what variety you have, avoid direct sunlight exposure to avoid burning their delicate leaves,
- A well-drained, slightly acidic potting soil is perfect for the Philippine evergreen. Ensure your Philippine evergreen has drainage holes at its base. If your soil is retaining too much water, mix in sand or perlite to your soil to aid drainage.
- Philippine evergreens should be watered thoroughly, but ensure the soil is dry before watering again. You can maintain this watering schedule through the spring, summer, and fall and taper off in the winter. Never allow the plant to dry out completely.
- Philippine evergreens don’t like cold drafts or temperatures below 70ºF. Keep your Philippine evergreen away from cool windows or vents. Remember, the warmer the climate, the better.
- Feed your Philippine evergreen twice yearly, at the beginning and end of its growing season, with slow-release pellets or liquid fertilizer.
According to my research, Philippine evergreens are unsafe for pets and children to consume but are safe to smell and touch. I recommend keeping them out of reach of small children and pets who may chew on them.
