Plants for a bathroom

The bathroom is sold as the easy room for plants, and it is not quite. It does have the highest humidity in the house, which suits ferns, calatheas and anything that browns at the edges elsewhere. It also usually has the worst light, the coldest nights and the smallest windowsill, often behind frosted glass that scatters what light there is.

So choose for the light first. A bathroom with a clear window that gets sun for part of the day will grow almost anything on this page. A bathroom with a small frosted pane and an extractor fan is a low light room that happens to get steamy, and the plants that suit it are the ones that suit a dim corner anywhere.

What the steam actually does

A shower raises the humidity of the room to near saturation for perhaps twenty minutes, and the fan then takes it back down. Averaged over a day the gain is real but modest. It is enough to stop a fern crisping and not enough to keep a plant that genuinely needs damp air alive on its own. If you want to grow something that demands humidity, group the pots together and stand them on a tray of damp pebbles, in the bathroom or anywhere else.

What the steam does do is settle on leaves, which is a small kindness. A plant in a bathroom needs dusting far less often than the same plant in a living room.

The cold at night

This is the part that catches people out. A bathroom is heated in bursts and then left, and the tiles and the porcelain hold cold. A tropical plant against an outside wall can spend the night five or six degrees below the rest of the house. The entries in the journal give a comfortable range for every plant, and if the room drops below the lower figure regularly the plant will sulk whatever the humidity is doing.

Move the pot off the sill and away from the outside wall, or shut the blind on a cold night with the plant on the room side of it rather than trapped between the blind and the glass, which is the coldest place in the house.

Watering in a humid room

Soil dries more slowly in a bathroom than in a dry living room, so the same plant needs water less often there. When you add a plant to your log and tell it which room it lives in, the room is a label rather than a calculation, so check the soil for the first month and set your own interval if the journal’s figure runs ahead of what the pot is doing.