You may have heard of the NASA study, conducted in 1989 by the National Aeronautics and Space Administration and the Associated Landscape Contractors of America. The goal of the study was to determine if plants were effective air purifiers, and specifically which plants cleaned which chemicals out of the air. NASA was hoping to find which plants would be ideal for filtering air at space stations. They actually found that there are many plants that efficiently remove chemicals from indoor air, some of which are more effective at certain chemicals than others. Since we’ve been talking about 23 Sources of Formaldehyde To Remove From Your Home, we wanted to share a few of the plants they found to be particularly efficient at removing formaldehyde.
As we have found, formaldehyde is harmful to our health and is present in most homes. A general rule of thumb, per NASA’s recommendation, is to add at least one houseplant per 100 sq. ft. in your home. This translates to about one houseplant per room in your house and anywhere from 10 to 20 in a home, depending on the size.
Here are the eight plants that we recommend if you are looking to reduce formaldehyde and add some greenery to your space. These plants are easy to maintain, many of them can tolerate lower light conditions, and will filter more than just formaldehyde out of your air. They’re an inexpensive, efficient, and beautiful way to improve your air quality!
Rubber trees are in the ficus (fig) family. They are very hearty plants to keep indoors and come in many varieties. Beware their milky latex, which only releases when you break the leaves. The latex from rubber trees is harmful if ingested. However, the plant got its “rubber” name because that same latex is used to make natural rubber. Rubber plants are tolerant of sparse watering, but do best in medium to high light. Always allow to dry between waterings.
Peace lilies are very easy to maintain, needing low to medium amounts of both water and sunlight. Peace lilies will even bloom in low light conditions. Although peace lilies do not need a lot of water, they will let you know they are thirsty as their leaves start to droop. Once watered, they quickly perk up again. Their leaves will start to yellow if they have too much sun. As with rubber trees, beware that ingesting the leaves can be harmful to humans and pets!
Named for its arachnid-like shape and growth pattern, spider plants make easy houseplants. Spider plants can tolerate low light conditions and don’t require much water. If the tips start to burn (turn dry and brown), it may be from the fluoride in your tap water. Spider plants bloom with delicate white flowers. They flourish in hanging baskets that can be rotated for good light distribution.
Money plants, also known as golden pothos, are durable, fast-growing plants. They naturally grow in a vine shape and will do well in a hanging basket or in a traditional pot. Happy with sparse waterings, money plants do best in medium to high light. However, their leaves stay green even in lower light conditions. They can even grow on top of aquariums, with their roots surviving on the water. Golden pothos should be out of reach of pets, who will have a toxic reaction to this plant.
Dumb cane, sometimes called a mother-in-law plant, likes moderate sunlight and watering. The “dumb” part of the name refers to the poisonous nature of the raphides on the plant, similar to peace lilies or money plants. As the plant grows, old leaves curl up and fall off to make room for new leaves. If you notice that the leaves start to yellow, the soil may be weak and it could be time to repot your dumb cane with new soil.
If you’re like me, you may find it hard to resist buying the occasional orchid at the grocery store. If you tend them carefully, orchids will last a long time and bloom again for you. I have yet to have luck with re-blooming, but orchids can stay alive for more than just their blooming season! When you purchase an orchid, particularly from a grocery store where they are potted a certain way to look attractive, there a few steps you should take right away. We recommend removing any florists moss and replanting in a pot that drains well. 8 Ways to Kill Your Orchid is an important article for debunking the myths about orchid-growing, including the ice-cube watering trick. Water orchids sparingly and be sure the soil drains well. Nourish the soil with a good orchid fertilizer to promote more blooms.
Glorious snake plants! No matter how green or not-green your thumb is, you can surely keep a snake plant alive – they may be the easiest houseplant in the land. Snake plants are very tolerant of many conditions and can thrive in even low light, which makes it great for nearly any place in your home. You also should be careful to avoid over-watering your snake plant and never water when the soil is still wet. Essentially, the more you leave your snake plant alone, the happier it will be! And rest assured knowing that it’s working hard to remove formaldehyde from your air.
Philodendrons are a big family of cheerful, ambitious growers that will quickly grow large if given the right conditions. There are many varieties of philodendrons, including some with larger leaves, some with heart-shaped leaves, variegated varieties, and even different colors. Most philodendrons prefer brighter light; as much indoor light as possible is best for your philodendron. However, philodendrons are very efficient with water and should dry out fully between waterings, which can be spaced 10 days apart or more. If you have a bright spot in your home that could use a large, sprawling plant, a philodendron might be right for you!
General tips for tending happy houseplants:
Introduce it slowly
If you are just bringing home a plant from the store, leave it in its plastic pot (even if you drop that inside the pot you will ultimately replant it in). Water frequently when you first bring it home, allowing the plastic pot to drain well. If you plan to move the plant into a darker area of your home, it’s a good idea to slowly acclimate the plant. Remember, it’s coming from a nursery where it is tended well and typically given great light. When you bring the plant inside in your home, it could go into shock if you immediately re-pot and put it in a shady corner. First, keep the pot in plastic in a sunny spot, then slowly move to closer to its destination. By the time you re-pot the plant, it should be fully acclimated. This may take a couple of weeks for optimal plant health.
Give your plants baths
The majority of plants hate nothing more than sitting in water. Over-watering is a far more common cause of plant decline than under-watering. So when in doubt, let your plants dry out a little! When you do water your plants, they want to get a really good soaking. The best way to do this is to actually corral your plants into the bath or shower and fully douse them. Allow to drain, then carry them back to their homes. Never pot in a container without drain holes. Classic terra cotta pots are really great for most plants because they breathe through the container on all sides and have a drain hole at the bottom.
Celebrate with new pots
If you keep your plants happy, they will outgrow their pots. Most plants are ready to graduate to a larger pot about every two years. It’s time to re-pot when you start seeing roots above the soil or it just generally looks too large for its pot. When choosing the next pot, select one that is 2” wider in diameter than the last pot and use fresh soil.
Fertilizing keeps plants healthy
Most plants will really benefit from an appropriate fertilizer during the warm months (spring to fall). Orchids require their own fertilizer blend, but many of the other plants can share a common fertilizer. Before foliar feeding (applying a liquid fertilizer to the leaves) make sure the leaves have been cleaned/dusted because a clean plant is more receptive to the nutrition.
What are your favorite houseplants? Any tips for novice houseplant keepers?
Ready to streamline your routine? Read Clare’s tricks in Safe + Simple: Tips from a Minimalist Mama.
Want another trick for improving indoor air quality? Find out why we’re loving Himalayan Pink Salt Lamps!
Keep reading about chemicals to avoid in your home: Common Chemicals to Avoid – A Branch Basics Series.