The Snake Plant, commonly known as Mother-in-Law’s Tongue, is a popular houseplant recognized for its upright, sword-like foliage and durability. Its widespread use is often linked to claims about its positive impact on indoor air quality, making it a frequent recommendation for bedrooms. These claims involve unique attributes concerning oxygen production at night and the removal of airborne pollutants. This article explores the scientific basis for these benefits and the practical considerations for keeping this plant in a sleeping environment.
Nighttime Oxygen Production and the CAM Cycle
The Snake Plant employs a specialized form of photosynthesis known as Crassulacean Acid Metabolism (CAM). This adaptation allows the plant to open its stomata, or leaf pores, primarily during the cooler nighttime hours. This nocturnal gas exchange is a water-saving strategy developed by plants in arid environments to minimize water loss during the day.
During the night, the plant absorbs carbon dioxide and stores it as malic acid within its cells. Once daylight returns, the stomata close, and the stored acid is broken down to release \(\text{CO}_2\) internally, fueling the light-dependent stage of photosynthesis and resulting in oxygen production. Because the \(\text{CO}_2\) is collected at night, the plant is sometimes credited with releasing oxygen during darkness.
While the plant does release a small amount of oxygen after dusk, the quantity is biologically insignificant for improving the air quality of a typical bedroom. Studies have shown that a large number of mature Snake Plants would produce only a negligible increase in ambient oxygen levels. A sleeping adult’s oxygen demand far exceeds the marginal output of a few potted plants. The primary advantage of the CAM cycle is the plant’s ability to take in carbon dioxide when other plants do not, which helps it survive in low-water conditions.
Air Filtration: Removing Indoor Volatile Compounds
A demonstrable benefit of the Snake Plant is its capacity to filter certain Volatile Organic Compounds (VOCs) from the air. VOCs are gaseous chemicals that off-gas from common household materials, including paints, furniture, carpets, and cleaning supplies often found in a bedroom setting. The plant’s ability to absorb and break down these compounds gained attention through the 1989 NASA Clean Air Study.
The Snake Plant is effective in reducing the concentrations of specific pollutants like formaldehyde, benzene, and trichloroethylene. Formaldehyde is released by pressed-wood products and fabrics; benzene is a solvent found in plastics; and trichloroethylene is an industrial solvent often present in adhesives. The cleansing action involves the plant’s leaves absorbing the VOCs and the microorganisms living in the potting soil.
These soil microbes metabolize the VOCs into less harmful substances. The combination of the plant and its root-soil system acts as a biofilter for the air. Placing a Snake Plant in a bedroom can contribute to a localized reduction of these specific airborne toxins.
Practical Care and Lighting Needs
The Snake Plant’s reputation as a good bedroom companion is also strongly supported by its undemanding care requirements, which make it suitable for individuals new to houseplants. It exhibits tolerance for a wide range of light conditions, easily surviving in the low-light environments typical of many bedrooms. Although it tolerates dim corners, the plant grows faster and displays more vibrant variegation if placed in bright, indirect light.
The plant’s succulent nature means it is highly drought-tolerant, requiring infrequent watering. It is particularly susceptible to root rot if overwatered, so the soil must be allowed to dry out completely between watering sessions. This minimal need for attention makes it an easy addition to a busy person’s living space.
The plant thrives in average indoor temperature ranges, typically between 65°F and 80°F, which aligns with standard indoor climate control. This resilience means it can be placed in various bedroom spots without constant monitoring.
Toxicity and Safety Concerns
The Snake Plant is considered mildly toxic if ingested due to saponins present in its leaves and sap. These compounds serve as a natural defense mechanism. Ingestion by humans or household pets can lead to gastrointestinal distress.
Symptoms are generally mild, including nausea, vomiting, and diarrhea. The bitter taste usually discourages most animals from consuming large quantities. To maintain safety, especially in homes with curious pets or children, it is advisable to place the Snake Plant on a high shelf or in a location that is inaccessible.