Mother: “Eat your vegetables!”
Junior: “But why?”
Mother: “Because they are good for you!”
But what if plants are good for us even if we don’t eat them? It turns out that quite a bit of research has been done on the benefits of houseplants for our health and well-being.
Air quality
Some of the best-known research on the benefits of houseplants was conducted in 1989 by NASA in collaboration with the Associated Landscape Contractors of America (ALCA). The NASA Clean Air Study investigated whether plants can be beneficial for air quality in space stations.
The results suggested that plants such as the variegated spider plant, dracaena, ficus and peace lily were among the most successful at absorbing carbon dioxide and removing volatile organic compounds (VOCs) such as benzene and formaldehyde in closed environments. This process became known as phytoremediation.
A summary of numerous intermediate studies on the effects of houseplants on air quality was published in 2020 by the Journal of Exposure Science and Environmental Epidemiology. It confirmed that houseplants, their soil and soil microorganisms absorb VOCs, but more research was needed to determine how variables interact before the findings can be applied in office and home environments.
For example, in 2023, an article published by the Penn State Extension Office cited research suggesting that it would take about 680 plants in a 1,500-square-foot home to achieve the same airflow effects as opening a few windows. So while plants help purify the air, it remains unclear how we can most effectively and efficiently harness this ability.
Cognitive and psychological benefits
Although more studies are needed to determine how efficient plants are at cleaning indoor air, research consistently shows that being close to plants helps us think better and feel better psychologically.
How do plants do this? An article in the International Journal of Wellbeing described three theories. The biophilia hypothesis states: “Since our ancestors evolved in wild environments and depended on the environment for their survival, we have an innate drive to connect with nature.”
That urge is harnessed by horticultural therapy, which has been used for centuries to increase the sense of well-being in people with mental health problems, dementia and other conditions. Medical clinics in Manchester, England, have gone so far as to ‘prescribe’ potted plants to patients with depression and anxiety. It has been shown that soils often contain microbacteria that work much like antidepressants to improve mood.
The stress reduction hypothesis states that spending time in nature triggers a physiological response that reduces stress levels. Jenny Seham, PhD, of Montefiore Health System in the Bronx, states that plants lower the stress hormone cortisol. A reduced cortisol level results in less fatigue, less irritability and lowered blood pressure.
The third theory, the attention recovery hypothesis, claims that nature essentially boosts our cognitive resources, aiding our ability to focus and pay attention.
Texas A&M showed that working and studying around factories improved quality and accuracy. Similarly, the University of Michigan found that mental activities in the presence of plants improved concentration, memory and productivity, with memory improving by 20%. A 2007 study found that people had fewer sick days when plants were in their workspace and were more productive.
It is estimated that modern humans spend as much as 80% of their time indoors. So having houseplants is like bringing nature inside, to our benefit.
Get well soon
Who hasn’t sent flowers or a plant to someone recovering from an illness, hoping to cheer them up? They can also promote the patient’s physical recovery.
In preparation for a 2002 Plants for People conference, Roger Ulrich, Ph.D., reviewed multiple studies on the impact of gardens and plants in healthcare.
He found that not only does greenery and even images of greenery reduce stress in patients, but that plants can also be helpful in reducing the amount of pain medication needed, speeding up recovery time, and enhancing the overall sense of well-being and satisfaction with the care provided. . Even job satisfaction and staff retention benefited from the proximity of plants in the hospital gardens.
Sleep better
Plants release oxygen during the day. But as light levels decrease after nightfall, photosynthesis stops, and instead of releasing oxygen, plants release carbon dioxide. So if you want a better night’s sleep, place orchids, succulents or bromeliads near your bed, as they still release oxygen in lower light. This increase in oxygen can help you fall asleep faster and sleep better overall.
Get started
Research confirms that houseplants have psychological and physical benefits, and that you find them beautiful. If you’re looking for inspiration, search the internet for ways to use plants in your home decor.
My search found MasterClass, which offers a course on displaying plants in your space. For example, small rootless air plants that absorb moisture from the air can be displayed in wire frames, glass planters and ceramic sculptures on wall shelves. A terrarium on a bookcase or side table creates a mini indoor garden.
A plant on the dining table can add some life to your meals. Hanging planters are of course a classic way to integrate plants into your room without taking up floor space. If floor space is not an issue, large potted plants and small trees really bring nature indoors.
How much is enough? Dr. Seham of Montefiore Health System recommends starting with one or two live plants in your indoor environment if you’re new to this. Getting too many at once and not being familiar with how to care for them can cause stress rather than reduce it. In her experience, Dr. Seham: “Just one plant can make a difference; it can captivate you by its scent or color, creating a positive mood response with every interaction.”
Another word of caution: Avoid plants on the invasive species list, even if kept indoors. Assistance in identifying invasive plants can be found on the UF/IFAS Center For Aquatic and Invasive Plants website (plant-directory.ifas.ufl.edu).
If you have young children and pets, care in selecting houseplants may be warranted. The ASPCA and the National Poison Control Center maintain lists of plants that can be harmful to people and pets. Keep in mind that just because it’s for sale somewhere doesn’t mean it’s safe for your specific pet and human family members.
So it turns out Mom and Junior are right: you don’t have to eat plants to be good for you!
Mary Janik is a Master Gardener volunteer with UF/IFAS Leon County Extension, an equal opportunity agency. For gardening questions, please email AskAMasterGardener@ifas.ufl.edu.
This article originally appeared on Tallahassee Democrat: From food to fresh air: How plants provide health benefits
