Indoor plants have become a trend in homes and offices, largely fueled by the idea that they purify the air. This myth started with the famous NASA Clean Air Study (1989), which showed that certain species could remove pollutants in sealed environments, improving indoor air quality by absorbing carbon dioxide and releasing oxygen during photosynthesis.
The catch is that the experiments were conducted in closed chambers, without windows or air circulation, which is very different from real life. More recent research, such as that by environmental scientist Richard L. Corsi, reveals that hundreds of plants would be needed in a single environment to achieve noticeable results. Plants do extract pollutants, but the amount is minimal in typical homes and offices.
So, if you’re thinking of replacing your air purifier with a fern, know that plants alone do not significantly improve air quality.
So, why have plants?
Even if the purifying effect is limited, the benefits of plants — and more broadly, of biophilia — are proven. Biophilia describes our natural affinity for the living world and shows that not only plants, but also elements such as natural light, colors, nature-inspired shapes, wallpaper, modular carpets, stone floors, or exposed wooden trellises can have positive impacts on indoor environments.
- Stress reduction – Research in the Journal of Physiological Anthropology shows that caring for plants reduces physical and psychological stress. Taking care of plants and watching them thrive provides a sense of responsibility and personal accomplishment.
- Mood improvement – Microorganisms in soil stimulate endorphins and serotonin, promoting a sense of well-being. A study from the University of Munich reinforces that even a brief visual contact with the color green improves creative performance.
- Physical health – Scandinavian studies indicate that offices with more plants report fewer symptoms such as headaches and coughs, as well as lower rates of sick leave.
- Productivity and creativity – The University of Exeter found that environments enriched with plants increased well-being by up to 47% and productivity by 38%.
- In a call center in California, employees with a view of greenery answered calls 6% to 7% faster. Based on this result, the company invested US$ 1,000 per employee to reorganize workspaces and provide views of vegetation for everyone. The outcome was impressive: an annual savings of US$ 2,990 per employee, with a return on investment in just four months and lasting gains in productivity and profits.
- Cognitive impact – A study conducted in Barcelona showed that the presence of vegetation in schools improved the cognitive development of elementary students, reinforcing how exposure to greenery directly affects learning and attention.
- Stress and anxiety reduction – A 2015 study from Stanford University showed that walking in a park helps urban residents stop ruminating, or mentally dwelling on negative thoughts associated with an increased risk of depression and other mental health issues. You can replicate this effect by bringing the outdoors inside with plants.
These results make it clear that indoor plants do not need to be “air purifiers” to be valuable. They are part of a set of biophilic strategies that transform homes and offices into healthier, more human, and more creative spaces.