The snake plant (Sansevieria trifasciata) is a popular houseplant often recommended for the bedroom based on the belief that it improves sleep quality. This succulent is distinct for its upright, sword-like leaves and thrives even with minimal care. Claims about its benefits center on its unique nighttime behavior and its ability to cleanse the air. This article examines the scientific evidence behind these claims.
The Nighttime Oxygen Myth
The most common claim supporting the snake plant’s bedroom placement is that it releases substantial amounts of oxygen while you sleep. Most plants perform photosynthesis during the day, releasing oxygen, but at night they primarily respire, consuming oxygen and releasing carbon dioxide. The snake plant is different because it uses a specialized process called Crassulacean Acid Metabolism (CAM photosynthesis).
This CAM process allows the plant to open its leaf pores, or stomata, only at night to absorb carbon dioxide, which is then stored for use during the day. Opening stomata during cooler night hours prevents excessive water loss, a key adaptation for arid environments. While the plant takes in carbon dioxide at night, the oxygen it releases is a byproduct of the daytime light-dependent reactions of photosynthesis.
Any oxygen released at night is an extremely small quantity compared to the total volume of air in a typical bedroom. The direct effect of a single houseplant on oxygen concentration is negligible for human respiration. An expert estimate suggests it would take the leaf area of hundreds of plants to produce the oxygen required by just one human in a day. Relying on a few snake plants to noticeably boost nighttime oxygen levels for improved sleep is not supported by the science of gas exchange.
Filtering Airborne Toxins
A more scientifically grounded benefit of the snake plant lies in its capacity to absorb volatile organic compounds (VOCs) from the air. VOCs are harmful chemical gases released from common household items like carpets, paints, cleaning products, and furniture. The snake plant filters common indoor toxins such as formaldehyde, benzene, xylene, and trichloroethylene.
These air purification abilities were highlighted by the 1989 NASA Clean Air Study, which investigated how plants could improve air quality in sealed environments like space stations. The plant absorbs these gaseous toxins through its leaves and transports them to the root zone, where soil microorganisms break them down. Removing these irritants can theoretically improve overall air quality, indirectly contributing to a more comfortable sleep environment.
The main caveat is that the study involved small, sealed chambers, unlike a typical home with constant air exchange. While the plant is effective at removing VOCs in controlled settings, the volume of air and the rate of air exchange in a modern home mean a single plant’s impact on overall air quality is often small. However, some recent studies suggest that Sansevieria trifasciata can be more effective at absorbing formaldehyde than certain air purifiers under specific conditions.
Beyond Air Quality: The Plant Effect
The benefits of placing a snake plant in the bedroom may relate more to psychology than chemistry. The mere presence of indoor plants has been linked to several documented psychological benefits. This connection is often explained by the biophilia hypothesis, which suggests humans have an innate tendency to seek connections with nature and other forms of life.
The calming presence of greenery helps reduce stress and lower anxiety levels, which are major obstacles to falling asleep. Studies show that interacting with plants reduces psychological and physiological stress, potentially lowering blood pressure and cortisol levels. Creating a visually appealing and natural sleeping environment promotes a sense of tranquility conducive to rest.
Indoor plants also contribute to minor environmental regulation. They release small amounts of water vapor through transpiration, slightly increasing room humidity. This subtle rise in humidity can help soothe dry skin and mucous membranes, potentially leading to a more comfortable night’s sleep, especially in dry climates.
Setting Realistic Expectations for Sleep Improvement
The snake plant is a pleasant addition to a bedroom, but it should not be viewed as a standalone cure for sleep issues. Its contributions to sleep quality are real but indirect, stemming primarily from psychological comfort and minor air purification, not from an oxygen boost. The plant’s ability to filter VOCs and its visually soothing presence work together to create a healthier and more relaxing environment.
To maximize the plant’s positive presence, proper placement and care are important. The snake plant is highly tolerant of low light and requires minimal watering, making it an ideal, low-maintenance bedroom companion. Place the plant where it can be seen and enjoyed, but ensure its soil dries out between waterings to prevent mold, which would counteract air quality benefits. While it will not replace an air purifier or address a medical sleep disorder, the snake plant offers a simple, natural way to cultivate a calmer atmosphere that supports better rest.