A bathroom looks like the perfect home for tropical plants: warm, steamy and rarely dry. Humidity does help some of them. But most bathrooms have small, frosted or shaded windows, and some have none. For most bathroom plants, the limit is light, not moisture.
University of Missouri Extension puts it plainly: lack of adequate light is the most common factor limiting plant growth in many areas of the home. So choose by light first, then use the humidity as a bonus.
What humidity does for houseplants
Iowa State Extension says many houseplants prefer 40–50% relative humidity, while homes in winter may drop to 10–20%. Low humidity can cause slow growth, dried-up flower buds and brown leaf tips and edges. University of Maryland Extension adds that all indoor plants except cacti and succulents benefit from higher humidity around them.
A bathroom can help with that. NC State suggests placing Boston fern near kitchens and bathrooms for higher humidity. Clemson HGIC says delicate ferns grow best in a terrarium or a very humid area such as a bathroom.
How humid your bathroom stays depends on how often it is used and how well it is ventilated. A small hygrometer tells you more than a guess. For other ways to raise humidity, see our humidity guide.
What humidity does not fix
Humidity does not replace light. University of Illinois Extension sets these minimum levels (one foot-candle is about 10.8 lux):
| Category | Illinois reference | Typical spot |
|---|---|---|
| Low | 75 foot-candles (about 810 lux) | A few feet from a north window; 1–3 m (3–10 ft) from an east or west window |
| Medium | 150 foot-candles (about 1,600 lux) | In front of a north window; a few feet from an east or west window |
| High or bright | 300 foot-candles (about 3,200 lux) | In front of an east or west window |
Measure at the spot the plant will sit, with the blind as you normally keep it. Below about 810 lux, even low-light plants need help from a grow light.
Bathroom plants by light and humidity need
Light ratings are from the Illinois Extension chart where the plant is listed, and from NC State or Clemson otherwise. Pet status is from the ASPCA.
| Plant | Light | Humidity and water | Size | Cats and dogs |
|---|---|---|---|---|
| Boston fern (Nephrolepis exaltata) | Low, about 810 lux (Illinois); bright, indirect preferred (NC State) | High humidity; never let it dry out | 61–91 cm (2–3 ft) | Non-toxic |
| Bird’s nest fern (Asplenium nidus) | Medium, about 1,600 lux (Illinois); north window (NC State) | Does not tolerate dry conditions; pebble tray may help | Clemson: to 46 cm (18 in) | Not listed |
| Maidenhair fern (Adiantum) | Light of a north window (Clemson) | About 50% humidity; soil moist at all times | 15–51 cm (6–20 in) | Not listed |
| Staghorn fern (Platycerium bifurcatum) | Medium, about 1,600 lux (Illinois) | Let roots dry slightly, never completely | Fronds 61–91 cm (2–3 ft) | Non-toxic |
| Rabbit’s foot fern (Davallia fejeensis) | Good indirect light (NC State) | Tolerates lower humidity than most ferns; top 1.3 cm (½ in) dry between waterings | Hanging or pot | Non-toxic |
| Nerve plant (Fittonia albivenis) | Bright to medium (NC State) | Leaves shrivel in dry air or drafts | 8–20 cm (3–8 in) | Non-toxic |
| Prayer plant (Maranta leuconeura) | Medium, about 1,600 lux (Illinois) | Requires high humidity; intolerant of low humidity | 15–30 cm (6–12 in) | Non-toxic |
| Peacock plant (Goeppertia makoyana) | Bright, indirect or partial shade (NC State) | About 60% humidity; moist, not soggy | 30–61 cm (1–2 ft) | Non-toxic (calathea) |
| Aluminum plant (Pilea cadierei) | Tolerates low light (Missouri) | Needs high humidity | 23–30 cm (9–12 in) | Non-toxic |
| Moth orchid (Phalaenopsis) | Low light; east windowsill best (NC State) | Warm, humid; bark mix, damp not soggy | 46–61 cm (18–24 in) | Non-toxic |
| Peace lily (Spathiphyllum) | Low, about 810 lux (Illinois); needs medium light to flower (Missouri) | Moist, not soggy | Often about 0.9 m (3 ft) indoors | Toxic |
| Chinese evergreen (Aglaonema) | Low, about 810 lux (Illinois) | Prefers high humidity; tolerates drier air | 30–51 cm (12–20 in) | Toxic |
| Heartleaf philodendron (Philodendron hederaceum) | Low, about 810 lux (Illinois) | Prefers medium humidity; tolerates dry air | Trailing stems to 1.8 m (6 ft) | Toxic |
Which plants gain most from a humid bathroom
Ferns. Clemson HGIC says thin, delicate ferns struggle with household humidity and that maidenhair ferns are difficult to grow in most homes. A bright, humid bathroom is one of the few places they do well. Bird’s nest fern is easier; Clemson calls it easy to grow. For Boston fern specifically, see our Boston fern bathroom guide, and see the maidenhair fern hub and staghorn fern hub.
Prayer plants and calatheas. NC State says prayer plant requires high humidity and is intolerant of cold drafts. Peacock plant needs about 60% humidity and may brown with fluoride in tap water. See our calathea and goeppertia care guide and the prayer plant hub.
Nerve plant and aluminum plant. Both stay small enough for a shelf or windowsill. NC State says nerve plant wilts dramatically when dry but recovers after watering, and performs well under fluorescent lights. See the nerve plant hub.
Moth orchid. NC State says moth orchids prefer low light, warm temperatures and high humidity. An east-facing bathroom window suits them. See the phalaenopsis hub.
Plants that gain little from the steam
Peace lily, Chinese evergreen and heartleaf philodendron tolerate low light and ordinary indoor air, so they suit dim bathrooms without needing the humidity. Cast iron plant is another: Missouri calls it one of the best plants where only low light exists, and Iowa State says it tolerates below-average humidity.
Snake plant, cacti and succulents prefer dry air. Iowa State notes snake plant prefers low humidity, and Maryland excludes cacti and succulents from plants that benefit from more humidity.
Watering in a humid room
Virginia Cooperative Extension notes that in high humidity, potting mix dries more slowly, so plants need water less often. Check before every watering. Illinois Extension recommends testing the mix with a finger to about 5 cm (2 in) deep and watering when it is dry, then emptying the saucer.
Iowa State advises against relying on misting: it raises humidity for only a few minutes and can spread disease.
A windowless bathroom
A bathroom with no window needs electric light for any plant. University of Missouri Extension recommends:
- 16–18 hours of light a day for plants that get no outdoor light, on a timer.
- 10–15 watts of fluorescent light per square foot (about 0.09 m²) for low-light plants; a single 2-foot 20-watt or 4-foot 40-watt tube suits low-light plants only.
- Plant tips 15–30 cm (6–12 in) from the tubes.
- Grounded fittings. Missouri stresses grounding because water is used around plants. In a bathroom, that matters even more.
See our grow lights for low-light apartments for setups.
How to choose
- Measure light at the exact spot, at midday.
- Under about 810 lux, choose cast iron plant, Chinese evergreen or heartleaf philodendron, or add a grow light. Our low-light plant guide has more options.
- With medium light and regular showers, choose ferns, prayer plants, nerve plant or a moth orchid.
- Keep plants away from heaters and vents. Maryland Extension says indoor plants are sensitive to drafts and heat from registers.
- Check pets. See our pet-safe plants guide.
References
- University of Illinois Extension: Houseplants: Lighting; Houseplants: Watering
- University of Missouri Extension, D. H. Trinklein (rev. 2016): Lighting Indoor Houseplants, G6515
- Iowa State University Extension: How to Care for Houseplants; How can I raise the relative humidity indoors for my houseplants?; Easy Low-Maintenance Houseplants
- University of Maryland Extension: Temperature and Humidity for Indoor Plants
- Virginia Cooperative Extension: Properly Watering Container Houseplants, SPES-804P
- Clemson Cooperative Extension HGIC: Indoor Ferns
- NC State Extension Gardener Plant Toolbox: Nephrolepis exaltata, Asplenium nidus, Platycerium bifurcatum, Davallia fejeensis, Fittonia albivenis, Maranta leuconeura, Goeppertia makoyana, Pilea cadierei, Phalaenopsis, Spathiphyllum, Aglaonema, Philodendron hederaceum
- ASPCA Animal Poison Control Center: Toxic and non-toxic plant list