When it's cold outside, many of us battle with condensation and even mould and damp patches in our homes. The internet is awash with claims that houseplants can reduce humidity and help beat condensation and mould. But this does not ring true, so we decided to investigate whether there is any truth to the claims.
More on house plants
Most of the online articles – if they cite any evidence at all – claim that houseplants can be used to reduce condensation and mould in damp, humid rooms. It is claimed that they can absorb moisture in the air through their leaves. Peace lily, Boston fern, ivy, spider plant, snake plant and orchids are just some of the recommended mould-beating plants. Among some of the claims we have read are that ivy "removes airborne mould" and that the snake plant is a "mould-loving" variety.
We're not biology experts but we could have sworn that at school, we learned that houseplants transpire through their leaves, releasing water into the atmosphere. So how can they possibly help beat condensation and mould?
None of this added up here at Gardens Illustrated so we contacted Guy Barter, chief horticulturalist at the RHS, for his opinion.
Can houseplants reduce condensation and mould?
"I am not so sure how plants can beat mould," said Guy. "Houseplants emit water vapour during transpiration, an unavoidable part of photosynthesis, necessary for the plant’s existence. This will contribute in a very small way to condensation in houses."
He added: "Most domestic condensation will come washing, cooking and people breathing."
Guy also pointed out that in centrally heated houses the air tends to be rather dry and some moisture in the air is more comfortable for people and indeed for plants. "To this extent, plants make houses more comfortable, not to mention a modicum of oxygen from photosynthesis if they are in good light and adequately watered."
Guy added: "Some internet sources suggest that plants absorb water thorough their leaves. This, I am afraid, is fanciful. It would save a lot of watering were it true."
He added: "In centrally heated houses, the air tends to be rather dry and some moisture in the air will be more comfortable for people and indeed for plants. So to this extent plants make houses more comfortable, not to mention the effect on feelings of well-being from plants decorating dwellings and a modicum of oxygen from photosynthesis if they are in good light and adequately watered.
"Insulation, heating and ventilation are more effective at controlling domestic excess humidity, condensation and mould."
In other words, make sure your home is insulated and well ventilated, turn on the heating – and get a dehumidifier.
