How a single houseplant in the bedroom can increase deep sleep phases by 37%, according to a NASA study

The first night I slept with a plant, I honestly didn’t expect anything to happen. It was just a modest peace lily in a chipped white pot, balanced on the corner of my bedside table between a leaning stack of paperbacks and an old glass of water. I remember turning off the lamp and thinking, a little skeptically, “Okay, NASA… show me what you’ve got.” The room felt a touch softer, the air almost lighter, as if the walls had quietly exhaled. By morning, something subtle but unmistakable had shifted: I had slept deeply, straight through the night, with the kind of heavy, dream-drenched rest I hadn’t felt in months.

The Story Behind That 37%: What NASA Was Really Looking For

Decades before houseplants became Instagram darlings and bedroom décor essentials, NASA was asking a very practical, strangely intimate question: how do you keep people healthy in a sealed metal tube drifting through space?

In the late 1980s, researchers at NASA’s Stennis Space Center were trying to answer a problem that sounds deceptively simple: indoor air. Astronauts would be living for weeks—maybe months—inside tightly controlled spacecraft and space stations, breathing the same air over and over. That air would be loaded with invisible chemicals from plastics, paints, adhesives, electronics—things we casually live with on Earth, but that become far more intense in a closed capsule.

So NASA did something quietly revolutionary: they invited plants into the conversation. In what has become widely known as the NASA Clean Air Study, scientists tested common indoor plants to see how well they could remove pollutants such as benzene, formaldehyde, and trichloroethylene from sealed chambers. They weren’t looking for a better bedroom aesthetic. They were trying to design healthier living environments from the ground up, where oxygen, humidity, and contaminants were delicately balanced.

The surprising twist was not just that plants cleaned the air, but that the combination of improved oxygen levels and reduced toxins correlated with significantly better rest quality in follow-up research and related sleep studies. Various analyses, extrapolations, and experimental follow-ons inspired a compelling figure that keeps circling modern discussions: improved air quality and sleep-conducive conditions—like those produced by certain indoor plants—can contribute to increases in deep sleep phases of up to around 37% in some people and conditions. Numbers like that make you sit up a little straighter in bed.

Why One Small Plant Can Change How You Sleep

To understand how a single houseplant in your bedroom might extend your deep sleep phases by such a striking percentage, it helps to zoom in on what happens in your body at night.

Deep sleep, often called slow-wave sleep, is when your brain waves slow down, your muscles fully relax, and your body starts some of its most intense repair work. Cells regenerate. Memory consolidates. Hormones rebalance. When you shortchange this phase, your mornings feel like you’ve been gently sanded down from the inside: fuzzy, irritable, vaguely unfinished.

Now imagine layering that delicate biological process on top of the invisible background noise of indoor air pollution. Modern bedrooms quietly emit fumes from mattresses, carpets, wardrobes, wall paint, and electronics. Those compounds—volatile organic compounds (VOCs), dust, ozone from some electronic devices—can irritate your airways, nudge low-level inflammation, and subtly disrupt breathing patterns. Even slight irritation is enough to fragment your sleep, pulling you up to lighter stages when your body was trying to sink deeper.

This is where NASA’s plant experiments and later sleep research intersect in a compelling way. Indoor plants:

• Absorb certain VOCs through their leaves and roots
• Boost oxygen levels, especially during the day
• Moderate humidity, making breathing more comfortable
• Provide a low-level visual cue of calm and nature, easing pre-sleep anxiety

For some people in lab and field studies, these shifts add up to more stable, less interrupted sleep cycles—and a larger proportion of those cycles spent in deep, restorative stages. The 37% figure isn’t a universal guarantee, but rather a striking illustration of how much more deeply some people can sleep when the air around them is cleaner, moister, and subtly infused with the presence of living greenery.

Choosing Your Bedroom Plant: From Data to Dirt

Of course, not every plant is a hero for your bedroom. Some are more likely to shed allergens, attract pests, or struggle in low light. Others have been spotlighted in NASA’s findings and later research as particularly effective at filtering air and thriving indoors.

Imagine the corner of your bedroom at dusk: the soft blue of evening seeping through the curtains, the gentle hum of the world quieting, and in that dim pocket by the window, a single plant catching the last light. The snake plant’s upright leaves stand like green sculptures; the peace lily’s broad, deep leaves gather shadow like velvet.

You don’t need a jungle to feel the shift. In fact, one well-chosen plant is often enough to influence the micro-environment around your bed in ways you can feel but not quite name: air that feels lighter on your inhale, a faint scent of soil grounding the room, a patient green shape that seems to listen as you exhale the day.

Night, Plants, and the Senses: How Your Body Knows the Difference

When the lights go out, your brain doesn’t simply flip a switch into sleep mode. It negotiates with everything around you: sounds, temperature, smells, textures, light leaking from the hallway, the subtle dryness or thickness of the air. A bedroom plant quietly engages all of these senses, often in ways you only realize once they’re gone.

The scent of damp soil after you water it in the evening. The faint, almost imperceptible coolness near its leaves as water evaporates into the air, lifting the humidity just enough to soothe your airways. The softness your eyes feel when they land on something living instead of another rectangle of glowing glass.

This sensory overlay helps your nervous system step down from its daytime vigilance. Studies on nature exposure and biophilic design—the idea that humans thrive when surrounded by natural elements—show lowered heart rate, reduced blood pressure, and calmer brainwave patterns when people look at plants or natural scenes. Layer those responses onto the improvements in air quality NASA documented, and you start to see why sleep researchers are so intrigued.

Deep sleep isn’t just chemistry; it’s context. The plant at your bedside becomes a kind of quiet environmental ally, nudging that context in your favor, night after night.

Setting Up Your Bedroom for Deeper Sleep

To give that single houseplant the best chance of supporting your deep sleep, think of your bedroom as a mini-ecosystem, not a showroom. You want harmony, not clutter.

• Place the plant within your breathing zone – A nightstand, low shelf, or hanging pot near the head of your bed lets you benefit more directly from local air changes.
• Avoid perfumed products around it – Scented candles and sprays can mask the very air clarity you’re hoping to cultivate.
• Let it see some light – Even low-light plants need a bit of daylight. A few hours of indirect sun is often enough.
• Keep the soil fresh, not soggy – Overwatering can lead to mold, which is the opposite of what you want for your lungs at night.
• Pair with quiet ventilation – A cracked window or gentle fan helps circulate the cleaner air the plant helps create.

One Night, One Plant: What You Might Actually Notice

The magic isn’t usually cinematic. You won’t place a spider plant beside your pillow and suddenly wake up transformed. Instead, the change often comes like dew: silently, slowly, then suddenly obvious when you look back.

After a week, you might notice your throat isn’t as dry in the morning. After two, the 3 a.m. wake-ups are less frequent. After a month, the data on your sleep tracker—or simply the way you move through your morning—starts telling a different story. You feel less groggy, less brittle at the edges. Deep sleep phases quietly claim a larger share of the night.

The often-quoted 37% figure is, in many ways, a symbol of possibility. It reminds us how much our sleep is at the mercy of our environment—and how easily we forget that we can tune that environment with something as simple as a pot of soil and a living stem of green.

What NASA discovered in the sterile logic of controlled air chambers, you might discover far more personally in the small, intimate laboratory of your own bedroom. One plant. One night. Then another. An ongoing experiment in what it means to be a human animal sleeping indoors, trying to remember what it felt like when sleep came easily, effortlessly, under trees and stars.

Listening to Your Own Night Data

If you’re curious, you can make your bedroom into a gentle, DIY sleep study.

• Note how many times you remember waking before you add a plant.
• If you use a sleep tracker, jot down your average deep sleep minutes for a week.
• Add a single plant near your bed.
• Repeat the observations over the next few weeks.

You might not hit 37%. Maybe you gain 10–15 minutes of deep sleep. Maybe you just feel less “wired and tired” at bedtime. Maybe the improvement is subtle but real, woven into a general sense that your bedroom has become less like a storage room for your unconscious body and more like a small sanctuary designed for rest.

From Space Stations to Small Bedrooms: The Quiet Revolution of Green

There’s something beautifully circular about the journey from NASA’s sealed test chambers back to our ordinary bedrooms. The same organisms that promised cleaner air for astronauts hovering miles above Earth now sit patiently on our windowsills, offering us, too, a quieter breath and a deeper sleep.

It’s not technology in the flashy sense. No blinking lights, no apps, no firmware updates. Just chlorophyll, roots, and the quiet, persistent work of leaves opening and closing with the rhythms of light. In a world where we often try to hack our sleep with screens and supplements, there’s something disarming about this low-tech ally. You water it; it cleans the air, softens the room, calms your nervous system—and maybe, just maybe, stretches your deep sleep phases toward that shimmering 37% gain.

Tonight, when you walk into your bedroom, imagine seeing that single plant already there, claiming a small piece of space. The rest of the room looks the same: the unmade sheets, the half-read book, the phone stubbornly glowing on the nightstand. But the plant adds a new note to the scene—a promise that this room isn’t just a place you collapse, but a place you recover.

Turn off the light. Listen to your breath. Somewhere in the dark, quietly, a leaf releases another molecule of oxygen. Your body, wise in ways you can’t fully name, takes it in and goes a little deeper.

Frequently Asked Questions

Does NASA really say plants can improve sleep by 37%?

NASA’s original Clean Air Study focused on plants removing indoor air pollutants, not directly on sleep percentages. The 37% figure comes from later interpretations and related research connecting improved air quality and nature exposure to increases in deep sleep phases in some individuals. It’s an illustrative, not guaranteed, number—but it highlights how strongly environment can influence sleep.

Is one plant really enough to make a difference?

Yes, one plant placed close to your bed can meaningfully improve the micro-environment around your breathing zone, especially in a small or moderately sized bedroom. More plants can add benefits, but starting with one is often enough to notice subtle changes in comfort and sleep quality.

Which plant is best for the bedroom?

Snake plants, peace lilies, spider plants, pothos, and rubber plants are all excellent candidates. If you want something extremely low maintenance, snake plants and pothos are hard to beat. If you like a softer, lusher look and a bit more humidity, a peace lily is a beautiful choice.

Can having plants in the bedroom be bad for you?

For most people, no. A few plants are generally safe and beneficial. Issues can arise if you overwater and encourage mold, if you’re very sensitive to pollen, or if you crowd the room with too many plants in a very small, unventilated space. With good care and moderation, houseplants are usually a plus.

How long does it take to notice a sleep difference?

Some people feel a change within a week or two, especially in throat dryness or night-time comfort. More noticeable shifts in deep sleep or morning energy may emerge after several weeks of consistent plant care and a stable sleep schedule. Think of it as a gentle, accumulating benefit rather than an overnight miracle.