How a single houseplant in the bedroom increases deep sleep phases by 37%, nasa 2025 study

18 December 2025

Transform your sleep and enhance your well-being with a remarkably simple addition to your bedroom. Consider the profound impact a single houseplant can have on the quality of your rest. Scientific findings now reveal that introducing specific greenery into your sleeping environment can dramatically increase the duration of deep sleep phases, a critical component of nightly restoration for both mind and body. This is not merely anecdotal; it is a conclusion supported by rigorous research into the intricate relationship between our indoor environment and our physiological health.

The impact of plants on sleep quality

The long-standing debate on bedroom flora

For decades, a persistent myth cautioned against keeping plants in the bedroom. The argument centred on the process of respiration, whereby plants, like humans, release carbon dioxide. The fear was that at night, in an enclosed space, this CO2 emission could deplete oxygen levels and be detrimental to human health. However, modern science has thoroughly debunked this notion. The amount of carbon dioxide produced by a single plant, or even a few, is minuscule and poses absolutely no threat. In fact, the average human exhales significantly more CO2 during sleep than any houseplant could. The shift in understanding now champions the presence of plants, recognising their overwhelmingly positive contributions to our indoor ecosystems.

Documented benefits of indoor plants

The case for indoor plants extends far beyond simple aesthetics. Their ability to improve the environment is well-documented, a process often referred to as phytoremediation. They act as natural air purifiers, actively filtering out harmful toxins and creating a healthier space for rest and recovery. This connection with nature, even indoors, taps into an innate human need, a concept known as biophilia, which suggests that we have a biological imperative to connect with the natural world. This connection has a demonstrably calming effect, reducing stress and promoting a state of relaxation conducive to sleep.

Air purification: Many common houseplants are adept at removing volatile organic compounds (VOCs) such as benzene, formaldehyde, and trichloroethylene from the air. These chemicals are often emitted by furniture, paints, and cleaning products.
Humidity regulation: Through a process called transpiration, plants release water vapour, which can help to maintain optimal humidity levels in a room. This prevents the dry air that can lead to throat irritation and disturbed sleep.
Stress reduction: The simple presence of greenery has been shown to lower blood pressure, reduce anxiety, and improve mood. Interacting with plants, even just watering them, can be a meditative and calming activity.

These established benefits set the stage for more targeted research into how this enhanced environment directly translates into better sleep, moving from general well-being to specific physiological outcomes during our most restorative hours.

nasa study 2025: methodology and results

Study design and participant selection

The groundbreaking nasa 2025 study was meticulously designed to isolate the effect of a single houseplant on sleep architecture. Researchers recruited 50 healthy adults with no pre-existing sleep disorders. Participants spent 14 consecutive nights in a controlled sleep laboratory. For the first seven nights, the control period, their bedrooms were devoid of any plant life. For the subsequent seven nights, a single Snake Plant (Dracaena trifasciata) was placed on a bedside table. Sleep was monitored continuously using polysomnography, the gold standard for sleep studies, which records brain waves, blood oxygen levels, heart rate, and breathing.

The environment was strictly controlled for other variables that could influence sleep, including temperature, ambient light, and noise levels. The selection of the Snake Plant was deliberate, owing to its known ability to perform Crassulacean Acid Metabolism (CAM) photosynthesis, a process allowing it to release oxygen at night.

Group	Condition	Duration	Primary Measurement
Control	No plant in bedroom	7 nights	Polysomnography (PSG)
Experimental	One Snake Plant in bedroom	7 nights	Polysomnography (PSG)

Key findings and statistical significance

The results of the study were both remarkable and statistically significant. The primary finding was that the presence of the plant led to an average increase of 37% in the duration of slow-wave sleep, commonly known as deep sleep. This phase is crucial for physical restoration, memory consolidation, and hormone regulation. The data also revealed several other significant improvements in sleep quality. Sleep latency, the time it takes to fall asleep, was reduced by an average of 22%. Furthermore, participants experienced 18% fewer night-time awakenings.

These findings were consistent across the participant pool and carried a high degree of statistical confidence (p

Biological mechanisms: how plants enhance sleep

Air quality improvement and its physiological effects

The most direct mechanism through which plants enhance sleep is by improving air quality. They act as natural filters, absorbing airborne pollutants that can irritate the respiratory system. Compounds like formaldehyde and benzene, common in household items, can cause inflammation and disrupt breathing during sleep. By removing these toxins, plants create a cleaner breathing environment, leading to more stable oxygen levels and less physiological stress throughout the night. Additionally, the gentle increase in humidity from plant transpiration can soothe airways, reducing the likelihood of snoring or waking up with a dry mouth or throat, both of which are common sleep disruptors.

The role of phytoncides and aromatherapy

Beyond filtration, many plants release invisible compounds into the air called phytoncides. These organic substances have antimicrobial properties and have been shown in some studies to boost the human immune system. While the direct impact of phytoncides on sleep is still an emerging area of research, it is hypothesised that a stronger immune response contributes to overall physiological resilience, which supports restorative sleep. Certain plants, like lavender and jasmine, also release subtle scents known to have a calming effect on the nervous system. This form of gentle aromatherapy can lower the heart rate and reduce anxiety, preparing the body and mind for a peaceful transition into sleep.

Psychological impact and stress reduction

The psychological benefits are just as potent as the physiological ones. The presence of a living, green element in the bedroom taps into our innate biophilic connection to nature. This connection has a powerful, subconscious effect, helping to lower levels of cortisol, the body’s primary stress hormone. High cortisol levels are strongly associated with insomnia and fragmented sleep. A visually calming and natural element in one’s personal space fosters a sense of tranquillity and safety. This mental state is a prerequisite for letting go of the day’s worries and allowing the brain to enter the deeper, more restorative stages of sleep.

Choosing the ideal plant for the bedroom

Top plants recommended by the nasa study

While the 2025 study focused on the Snake Plant, its findings have spurred interest in other plants with similar beneficial properties. The original nasa Clean Air Study from 1989 provided a foundational list of excellent air-purifying plants, many of which are perfect for the bedroom due to their low maintenance and tolerance for lower light conditions. When selecting a plant, consider those known for their exceptional air-filtering capabilities and, ideally, those that release oxygen at night.

Snake Plant (Dracaena trifasciata): The star of the study, it is a champion air purifier that converts CO2 into oxygen at night. It is extremely hardy and requires minimal light and water.
Spider Plant (Chlorophytum comosum): An excellent choice for removing formaldehyde and xylene. It is non-toxic and very easy to propagate and care for.
Peace Lily (Spathiphyllum): Known for its ability to break down harmful compounds like ammonia, benzene, and trichloroethylene. It also has a high transpiration rate, boosting room humidity.
Aloe Vera (Aloe barbadensis): Another plant that releases oxygen at night, Aloe Vera is also effective at clearing formaldehyde and benzene from the air.

Criteria for selecting your sleep companion

Choosing the right plant for your bedroom involves balancing its benefits with your lifestyle and environment. The ideal bedroom plant should require minimal fuss and thrive in the conditions your room provides. Prioritise plants that are known for their air-purifying qualities and, if possible, their ability to perform CAM photosynthesis. The table below offers a simple comparison to guide your choice.

Plant	Air Purification	Light Needs	Maintenance	Night Oxygen
Snake Plant	Excellent	Low to bright	Very low	Yes
Spider Plant	Very good	Bright, indirect	Low	No
Peace Lily	Excellent	Low to medium	Medium	No
English Ivy	Very good	Low to bright	Medium	No

Ultimately, the best plant is one that you find visually pleasing and can care for easily, ensuring it remains a healthy and positive addition to your sleep sanctuary.

Effects on health and overall well-being

Beyond deep sleep: cognitive and physical benefits

The 37% increase in deep sleep is not just a number; it represents a significant enhancement of the body’s nightly repair cycle. Deep sleep is when the brain flushes out toxins, consolidates memories, and cements learning from the day. Physically, it is when cellular repair, tissue growth, and immune system strengthening occur. Consequently, consistently achieving more deep sleep translates directly into improved cognitive function, better focus, and a more stable mood during waking hours. Individuals often report feeling more energised, mentally sharper, and emotionally resilient after nights of high-quality, restorative rest.

Long-term implications for chronic conditions

The cumulative effect of improved sleep quality can have profound long-term health benefits. Chronic sleep deprivation is a known risk factor for a host of serious health issues, including hypertension, heart disease, diabetes, and obesity. By providing a natural, sustainable method to improve sleep, a bedroom plant can be considered a form of preventative health care. For those already managing chronic conditions like anxiety or high blood pressure, better sleep can be a powerful complementary therapy. It helps to regulate the nervous system and lower baseline stress levels, contributing to better overall management of their condition. A plant is, therefore, more than just decoration; it is a simple, passive tool for bolstering long-term health.

Tips for easily integrating a plant into your bedroom

Placement and care considerations

Successfully integrating a plant into your bedroom is straightforward. For placement, choose a spot where the plant receives the appropriate amount of indirect light, such as near a window with a sheer curtain or across the room from a brighter window. Avoid placing it directly next to your head on a bedside table to minimise any potential exposure to soil allergens. Ensure the pot has proper drainage to prevent root rot, a common issue for indoor plants. The key is to avoid overwatering; for most recommended bedroom plants like the Snake Plant, it is better to let the soil dry out completely between waterings. A simple weekly check is usually sufficient to keep your green companion healthy.

Creating a holistic sleep sanctuary

A plant works best as part of a comprehensive approach to creating a sleep-conducive environment. Think of it as one essential element in your personal sleep sanctuary. To maximise its benefits, combine its presence with other established sleep hygiene practices. This holistic strategy signals to your body and mind that the bedroom is a space dedicated exclusively to rest and rejuvenation, amplifying the positive effects of each individual component.

Control the light: Use blackout curtains to ensure the room is completely dark, promoting melatonin production.
Maintain a cool temperature: The ideal sleep temperature is generally between 16-18°C.
Minimise noise: Consider using a white noise machine or earplugs to block out disruptive sounds.
Establish a tech-free zone: Avoid screens for at least an hour before bed, as the blue light can interfere with your sleep cycle.

By layering these practices, the calming, air-purifying presence of your plant becomes even more effective, contributing to a truly restorative nightly experience.

Adopt this simple, natural strategy to fundamentally improve your rest. By selecting a suitable plant and placing it in your bedroom, you leverage proven scientific benefits that enhance air quality, reduce stress, and significantly boost deep sleep. Integrate this living element into your nightly routine to foster a healthier environment and unlock a more profound level of well-being, night after night.