Bathroom plants - which ones survive without a window and which do not
Which bathroom plants handle humidity and low light, what a windowless bathroom can really hold, and what a plant does not do about damp air.
The bathroom plants that hold up best are the Boston fern, the peace lily, the pothos and the ZZ plant. Which of them you can use depends on how much light your bathroom gets. The humidity from the shower only helps a plant that already has enough light.
The best plants for a bathroom, and what each one needs
Ferns and calatheas are the best plants for bathroom humidity. The air in a bathroom is more humid than in the rest of the house, and that is the air they need. Of the two ferns, the Boston fern takes less light, and the maidenhair fern wants a bright bathroom out of direct sun.
The ZZ plant and the snake plant tolerate a dim room but get nothing from the steam. They are the fallback for a dark bathroom, and the snake plant also prefers dry air. Between the two groups sit the Pothos, the peace lily and the spider plant, which tolerate low light and cope with humidity without needing it.
Start with the light column when you choose. If your bathroom is dim, rule out the maidenhair fern and the calathea, the two species in the table that do not tolerate shade.
Bathroom plants with no light: how much light your bathroom actually gets
Your bathroom almost certainly gets less light than it seems. The window is usually small, and light intensity drops fast as you move away from it. N.C. Cooperative Extension notes that a plant moved about 2.5 metres back from a south-facing window is already in low light. A Snake plant at that distance stays alive, but it leans towards the glass and adds new leaves slowly.
Illinois Extension puts low light at 75 foot-candles, against 10,000 to 12,000 outdoors in full sun. Only a small fraction of that reaches a room, even one that looks bright. The shadow of your hand tells you which light level you are in.
A faint shadow means you need low light plants for bathroom corners like yours, the tolerant group in the table. They grow more slowly and stay smaller, and extra water will not fix that, because what they lack is light. If your whole home is that dim, the choice is the same as for low light houseplants in any room.
What a bathroom with no windows will hold
A bathroom with no windows will not keep a live plant going. Plants need natural light, and the Royal Horticultural Society says a windowless bathroom is not suitable for growing live plants. Leaving the door open lets in some light from the hall, but it arrives weak, because intensity drops fast with distance. A ceiling bulb is no substitute, because it hangs far from the leaves.
If you want plants for bathroom with no windows anyway, you have two real options. One is a grow light on a timer, and under it the ZZ plant, the pothos and the Peace lily cope best. The other is to keep the plant by a window and bring it into the bathroom for a few days at a time.
Do bathroom plants absorb moisture from the room?
No, a plant does not noticeably dry out a bathroom. It takes water up through its roots and releases most of it through its leaves, so it adds water vapour to the air instead of removing it.
A plant does not prevent mould either, which is the other promise attached to bathroom plants that absorb moisture. The EPA advises keeping indoor relative humidity below 60 per cent. Without ventilation, it notes, moisture from the shower builds up and mould can grow. The American Lung Association concludes that houseplants do not improve air quality, and that overwatering can cause mould to grow on the soil.
Humidity does help ferns, which dry at the tips in the drier air elsewhere in the house. The Maidenhair fern is the clearest case, because it thrives in humid air and the RHS places it in a bright bathroom out of direct sun.
Where to put plants in a bathroom
Put a plant where the bathroom gets the most light, usually the shelf nearest the window. Height and distance change the light, because intensity drops fast as you move away from a small window. Bathroom shower plants follow the same rule, so do the hand test on the shelf inside the enclosure. Keep the snake plant out of the enclosure, because it dislikes steam.
On a wall, the position is fixed, so you cannot move the plant closer to the window in winter. The light also arrives from the same side every day, so the plant tends to lean towards the glass. The pocket on a Living Canvas, for example, holds about what a 15 cm pot takes.
Hanging a pocket on the wall means drilling. On tiles, put masking tape over the spot and use a tile bit. In plasterboard, an ordinary plug will not grip, so you need a plasterboard fixing. Hang the pocket at eye level or a little below, where window light usually still reaches. The mounting guide does it with one hole and one hook.
Hanging plants for a bathroom, and what they need up there
A hanging plant sits higher than everything else in the room, which helps only if it hangs within reach of the window light. It is also the pot you see least, so hang it where you can check the substrate with a finger without climbing on a stool.
Of the species in the table, the pothos, the spider plant and the Boston fern trail, so they suit a hook or a high shelf. Bathroom hanging plants still follow the light rule, so hang them where the hand test gives at least a soft shadow.
Small bathroom plants and why they dry out faster
A small pot holds less substrate, so a plant in a small pot dries out faster than the same species in a large pot. What sets the pace is the volume of substrate and not the size of the plant. By that measure a wall pocket is a small container, whatever board it hangs on, and needs checking more often.
Air plants in bathroom conditions are the exception, because they grow without substrate. The RHS notes that in the wild they grow on trees and absorb moisture from the air, which is why a humid bathroom suits them. They still need enough light, so a bathroom with no window fails them for the same reason it fails every other plant.
What we checked about bathroom plants
The light and humidity figures on this page come from university extension services and public health bodies, each linked where it is used. The pocket measurement was taken on the piece. Where something has not been measured, the page gives you the mechanism and the check instead of a number.
Conclusion - bathroom plants
Check the light first, before you buy plants for the bathroom. If your hand casts a soft shadow there at midday, the whole table is open to you, ferns and calatheas included. If the shadow is faint, stay with the ZZ plant, the pothos or the peace lily and water less than you think. If the room has no window at all, the decision is a grow light or a different room.
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