When it comes to the relationship between houseplants and allergy symptoms, there are two schools of thought. Some people think that plants can help remove airborne allergy triggers while others claim that plants only serve to introduce more allergens into the air. Both theories are correct to a certain extent, depending on the species of plant that you are talking about. Below, we discuss which ones could be the best indoor plants for people with allergies, and which plants people with allergies should try to avoid.
Can indoor plants help with allergies?
If someone in your household has allergies, you know how important it is to avoid bringing allergens into your home. Fortunately, you do not have to let your caution keep you from adding some plant life to your home decor. Not all houseplants will trigger allergy symptoms in those with allergic rhinitis. In fact, some plants may even be able to improve the air quality of your home. In the next section, we will discuss the allergens that plants may bring into your home, but first, let us take a look at the potential for houseplants to remove pollutants from the air that you breathe.
In 1989, NASA released a Clean Air Study that suggested that certain low-light plants may be effective in removing volatile organic compounds (VOCs) such as benzene, toluene, xylenes and formaldehyde from the air in energy-efficient buildings (Wolverton, et. al, 1989. We now know that there is an observed relationship between VOC exposure and the development of allergy-related respiratory systems (Choi, et. al, 2010). Because of this relationship, some people use the NASA study to claim that plants, such as florist’s chrysanthemum, can improve allergy symptoms by purifying the air in a home.
However, the Wolverton study was performed in a lab with no air ventilation, which is not indicative of the current state of buildings (but would be appropriate if applied to a dwelling in space, as discussed in the report). Here on earth, even newer, energy-efficient buildings have some exchange of indoor and outdoor air. Unfortunately, according to the EPA, houseplants are not an effective way to remove airborne pollutants inside of a building with normal ventilation and air exchange.
Note: Though you would need an impractical number of plants and an impossibly-airtight house to benefit from the air purifying aspects of today’s common houseplants, researchers are working on genetically modifying plants to remove significant concentrations of VOCs from the air. For example, a team at the University of Washington, led by Dr. Stuart E. Strand has already modified a pothos ivy plant to remove considerably more benzene and chloroform from the air than normal houseplants.
Best plants for air quality
Though common houseplants cannot compete with the pollutant-removing capabilities of actual air purifiers, you may still benefit from adding them to your home. In addition to the decorative and psychological value of indoor plant life, the following plants have been found to remove harmful VOCs from the air, which may be helpful, even in small amounts (and it certainly will not hurt). These houseplants were also found to be easy to grow and maintain, as well as resistant to insect infestation (Claudio, 2011).
- Areca palm
- Lady palm
- Bamboo palm
- Rubber plant
- English ivy
- Dwarf date palm
- Boston fern
- Peace lily
Note: Dracaena plants, English ivy and peace lilies are toxic to dogs and cats, according to the ASPCA. Exposure to these plants can cause severe adverse reactions in pets that include vomiting, diarrhea, drooling, oral irritation, abdominal pain, anorexia and depression.
Can indoor plants cause allergies?
When you have an allergic reaction to a plant, it means that your immune system is overreacting to exposure to an allergen released by the plant. The main allergens to consider when selecting plants are pollen and mold. When inhaled, these airborne pollutants can cause allergy symptoms such as sneezing, runny or stuffy nose, red and watery eyes, and dry, scaling skin in sensitive individuals. If you are looking for a houseplant that is least likely to bring allergens into your home, consider the following:
- Some plants produce more pollen than others. If anyone in your household is sensitive to pollen, it is worth a few minutes of research to avoid bringing a major pollen-producer into your home.
- Plants with large, flat leaves can quickly accumulate dust, which can trigger allergy symptoms in some individuals.
- Consistently damp soil is more likely to grow mold. Choosing houseplants that do not have to be watered often can help prevent mold growth in plant pots.
- Adding aquarium rocks to the bottom of your plant’s pot can help drain the water from the soil and decrease the likelihood of mold growth.
- Houseplants can increase the relative humidity in a room, according to the CDC, which can promote mold growth. A dehumidifier can help counteract the increased humidity caused by plants.
Some houseplants may cause an adverse reaction that is entirely separate from any allergen, such as the swelling and itchy, burning rash caused by exposure to stinging nettle. This effect is caused by histamine released by the plant when its hairs penetrate a person’s skin, and it affects people regardless of their allergic sensitivity. Another type of non-allergic reaction is phytophotodermatitis, a rash and skin discoloration caused by exposure to chemicals present in certain plants, such as Queen Anne’s lace, and subsequent exposure to sunlight.
Plants that cause allergic reactions such as allergic contact dermatitis or hives include poison ivy, lilies, chrysanthemums, dandelions, goldenrod, daisies and tulips. Like stinging nettle and Queen Anne’s lace, the plants mentioned above can cause severe health effects, but only in those that are allergic to the chemicals present in these plants.
Worst plants for allergies
Even if you are not expecting your new houseplant to do wonders for your indoor air quality, you will still want to make sure that it will not cause an allergic reaction in any of the members of your household. The following plants are likely to cause symptoms in those with allergic rhinitis.
- Chrysanthemums, common ferns, lilies and geraniums have been found to produce airborne allergens that can cause contact dermatitis, according to the Institute of Medicine’s 1993 book, Indoor Allergens. Additionally, tulips and lilies can cause hives in those who are allergic.
- Ornamental plants, including yucca, ivy, palm trees, and Ficus benjamina (weeping fig), can cause adverse reactions in those with allergies (Mahillon, et. al, 2006).
- Hoya compacta, a popular succulent vine also referred to as “wax plant,” can cause respiratory symptoms such as nasal congestion, runny nose, and sneezing (Sherson, et. al, 2017).
- Pine trees used for decoration around the holidays can harbor weed pollen produced during the fall months that has settled on the plant’s branches, according to the American College of Allergy, Asthma & Immunology (ACAAI). This weed pollen can cause allergic reactions in some individuals.
Though they may not be able to make drastic improvements to the air quality of your home, houseplants can still be an eye-catching decor choice that can incorporate a piece of nature into any room. As long as you take care to prevent soil mold growth and avoid the small fraction of houseplants known to cause a reaction in those with allergies, you should have no trouble adding new plant life to your home. For other tips and solutions for indoor allergies, read our article, “How to Get Rid of Allergens in Every Room of Your Home.”