Bringing elements of nature indoors has become a popular trend, transforming personal spaces into calmer environments. The presence of greenery offers an immediate aesthetic appeal that many find soothing. Placing living things in the room where you spend a third of your life naturally raises questions about their safety and practical benefits. This article addresses the common concerns and scientific evidence to determine if houseplants are a beneficial addition to your sleeping space.
Addressing the Nighttime Oxygen Concern
A long-standing myth suggests that plants in a bedroom are dangerous because they consume oxygen and release carbon dioxide (\(\text{CO}_2\)) while you sleep. This belief stems from a misunderstanding of plant biology, specifically the process of cellular respiration. Like all living organisms, plants respire continuously, taking in oxygen and emitting \(\text{CO}_2\) as they convert stored sugars into energy.
At night, without light, photosynthesis stops, meaning the plant no longer absorbs \(\text{CO}_2\) and releases oxygen. While the plant’s nighttime \(\text{CO}_2\) output is slightly greater than its oxygen output, the total quantity of gas exchanged is negligible. A single sleeping human releases exponentially more \(\text{CO}_2\) than a typical potted houseplant. Elevated \(\text{CO}_2\) levels are far more likely to result from sharing the room with a partner or a pet than from standard houseplants.
Measurable Health and Psychological Benefits
Indoor plants offer positive effects that extend beyond simple decoration, particularly for mental well-being. Studies show that interacting with plants can reduce both physiological and psychological stress responses. The presence of greenery has been linked to lower blood pressure and reduced levels of the stress hormone cortisol. This calming effect is attributed to biophilic design, which taps into the innate human connection to nature, fostering tranquility and improved mood.
Another benefit involves the plant’s capacity to filter Volatile Organic Compounds (\(\text{VOC}\)s) from the air. \(\text{VOC}\)s like formaldehyde, benzene, and trichloroethylene are emitted by household items such as furniture, carpets, and cleaning products. The 1989 \(\text{NASA}\) Clean Air Study demonstrated that certain plants could effectively remove these pollutants in small, sealed laboratory chambers. While this effect is undeniable in a controlled environment, it is important to understand the scale.
In a typical home with natural ventilation, airflow is generally the main factor in removing \(\text{VOC}\)s. For a houseplant to significantly improve the air quality of an average-sized room, an extremely high density of plants is required, far more than is practical. Therefore, the primary and most measurable benefit of bedroom plants lies in their positive psychological impact, with air purification acting as a small, supplemental benefit.
Safety and Practical Considerations
When choosing plants for a bedroom, safety is the first consideration, especially if small children or pets are present. Many common houseplants contain compounds that are toxic if ingested. For instance, the popular Peace Lily and Pothos contain insoluble calcium oxalate crystals, which can cause intense oral irritation, vomiting, and difficulty swallowing in pets. Other favorites, like the Snake Plant and \(\text{ZZ}\) Plant, contain saponins or other toxins that can lead to gastrointestinal distress.
It is prudent to consult the \(\text{ASPCA}\) toxicity list for every plant and place any questionable species completely out of reach. Beyond toxicity, maintenance issues can unintentionally compromise indoor air quality. Overwatering is the biggest cause of problems, creating a perpetually moist environment that attracts small insects known as fungus gnats.
Excessive moisture in the soil also promotes the growth of mold, which releases spores into the air. For individuals with allergies or asthma, this can exacerbate respiratory symptoms. Mitigating these risks requires careful watering, allowing the top inch of soil to dry out completely before adding more water, and ensuring pots have adequate drainage.
Top Low-Light, Air-Purifying Plant Recommendations
For bedrooms with limited natural light, selecting species that tolerate dim conditions is necessary.
Snake Plant (Dracaena trifasciata)
Also known as Mother-in-Law’s Tongue, this is one of the most resilient options. It uses \(\text{CAM}\) photosynthesis, allowing it to keep its stomata closed during the day and open at night to absorb \(\text{CO}_2\).
Other excellent low-light choices include:
- Spider Plant (Chlorophytum comosum): Known for its rapid growth and ability to filter airborne formaldehyde. This plant is non-toxic to both cats and dogs, making it a safer option for households with curious animals.
- Peace Lily (Spathiphyllum): Thrives in low light and humidity, filtering a range of pollutants including ammonia and benzene. Note that this plant has moderate toxicity and should be placed out of reach.
- \(\text{ZZ}\) Plant (Zamioculcas zamiifolia): Nearly indestructible, requiring very little water and tolerating extreme shade. Due to moderate toxicity, it should be placed on high shelves or in rooms inaccessible to pets and young children.