Calathea: the rainforest houseplant that reduces humidity and mould

Many people reach straight for chemicals or pricey electric dehumidifiers as soon as they spot mould or damp walls. Yet the answer is often sitting quietly in a plant pot: certain houseplants can draw excess moisture directly from the air. One type stands out in particular - it comes from the rainforest, copes well in low light, and can even rival popular favourites such as orchids when it comes to humidity.

The rainforest plant that practically soaks up moisture

This is the Calathea, also known as the prayer plant. It originates from tropical forests in South America, where conditions are consistently warm and humid. Those same conditions are common in many bathrooms, kitchens and poorly ventilated bedrooms - which is exactly why Calathea tends to thrive there.

The broad, often strikingly patterned leaves of the Calathea act like natural sponges: they absorb moisture from the indoor air and then release it gradually.

That helps steady the indoor climate. In very humid rooms, the relative humidity can drop slightly; in very dry rooms, it can rise a little. In homes with limited ventilation - or bathrooms without windows - this can make a noticeable difference: less condensation on mirrors, less musty odour, and less of a breeding ground for mould.

Why Calathea suits your home better than many trending plants

The key point is simple: Calathea doesn’t need blazing sunshine. Many popular houseplants - for example, a lot of succulents or certain orchids - quickly deteriorate in darker corners. Calathea, by contrast, is happiest in partial shade through to shade.

A perfect candidate for tricky spaces

• Ideal for humid rooms: bathroom, kitchen, utility room
• Happy in shade: works even in corners without direct sun
• Improves humidity levels: helps balance overly damp air as well as very dry air
• Visually striking: bold leaf patterns and large leaves

So if you’ve been frustrated because plants keep dying in an internal bathroom, Calathea is a much stronger option. It copes with conditions that cause many other plants to fail.

Care: looks demanding, but surprisingly straightforward

At first glance, Calathea can seem like a real “diva”: big, tropical and patterned. In day-to-day reality, though, it’s tougher than many people assume. It does need regular attention, but it will usually forgive the occasional lapse.

Watering, position, temperature - what it likes

Aspect	What Calathea prefers
Watering	lightly moist compost, no waterlogging; smaller amounts more often
Light	bright to semi-shaded, but no direct sun; shaded corners are possible
Temperature	warm; ideally between 20 and 26 degrees; no draughts
Humidity	enjoys humid air, making it perfect for bathrooms and kitchens

If you miss a watering once, you don’t need to assume it will immediately shrivel up. Calathea generally copes well with a skipped day. Constant wetness is the bigger risk: if the pot sits in water all the time, the roots can rot.

A good rule of thumb: let the top layer of compost dry slightly, while the compost underneath remains lightly moist - that usually means the watering level is about right.

Where Calathea is best placed in the home

What matters most is a warm spot without draughts. Cold hallways, frequently opened windows, or draughty patio doors can stress the plant over time. These locations tend to work well:

• An internal bathroom with steady temperatures
• A kitchen with higher humidity, but not right next to intense heat from the hob
• A living-room corner with indirect light
• A bedroom positioned away from direct radiator heat

Strong midday sun can quickly cause brown patches on the leaves. A north-facing window, or a position 2–3 metres back from a window, is often a better fit.

Other plants that can reduce humidity

Calathea isn’t the only “living dehumidifier”, but it’s among the most effective for humid, low-light rooms. If you’d like to mix and match, there are other species that perform well in studies and real-world tests.

Four alternatives with a strong impact

• Spathiphyllum (peace lily): tolerates partial shade, filters pollutants, and its large leaves help take up moisture. A popular choice for offices and living rooms.
• Chlorophytum comosum (spider plant): low-maintenance, multiplies quickly, and suits kitchens and hallways. Also works well in hanging baskets.
• Aglaonema: likes shade, needs little light, and handles stable conditions well. Great for darker corners with a bit of moisture.
• Bamboo palm: produces dense, fine leaves with lots of surface area. Particularly effective in larger rooms with higher humidity.

All of these plants influence humidity through their natural water cycle. They take up water through their roots, release some of it through their leaves, and in the process bind moisture from the air.

How much plants really help with damp

Plants won’t replace a professional building dryer if water has penetrated walls or the screed. In typical everyday situations - wet towels in the bathroom, condensation on windows, humid air after cooking - several large plants can still provide noticeable relief.

A single pot with a Calathea is unlikely to solve a mould problem in a poorly insulated period property on its own. Several pots spread across the bathroom, kitchen and bedroom have a far stronger effect. Add regular ventilation and avoid pushing furniture right up against external walls, and the indoor climate improves further.

Risks, common mistakes, and what households should watch for

The issues most often seen with Calathea are brown leaf edges and curled leaves. This usually points to air that’s too dry or exposure to draughts. If the plant sits directly above a radiator, it’s almost inevitable.

Worth noting for households with children or pets: many Calathea varieties are considered non-toxic. If you want to be completely sure, check the retailer’s guidance when buying. If in doubt, place the plant out of reach of cats that like to chew.

Practical tips for a “green dehumidifier plan”

A well-chosen plant combination can make day-to-day life noticeably more comfortable. One workable setup could look like this:

• In the bathroom, place one larger Calathea and one Spathiphyllum.
• In the kitchen, hang a spider plant in a basket and put a small Calathea on the worktop - with space away from the hob and sink.
• In the bedroom, stand a bamboo palm in a corner, away from the radiator.

If you also air rooms briefly but thoroughly twice a day, humidity usually stays within a comfortable range. A simple hygrometer from a DIY shop will show whether it’s working: readings between 40 and 60 percent are generally considered a good range for living spaces.

One more detail that’s often overlooked: leaf surfaces need to stay clean. Dust on the leaves slows their exchange with the air. Wiping the leaves once a month with a soft, slightly damp cloth is usually enough.