Can house plants cause damp?

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House plants CAN cause damp, but as long as you’re careful not to overwater them, then you should be fine.

If you’re worried about damp, don’t worry about turning on the dehumidifier. Removing excess moisture from the air helps to keep rooms warmer (because it takes more energy to heat water molecules than just regular air) which your plants will probably appreciate more than the humid air.

Many tropical house plants do love humidity, BUT they love staying warm a little bit more.

monstera leaf

So, do houseplants cause damp?

In short, no. I conducted a bit of research (googled it) and whilst some sites do claim that houseplants can cause damp, it’s unlikely to be the primary cause.

In long, possibly, but only if you have a jungle’s worth of plants that you’re overwatering a lot.

EDIT: I have 100+ plants. I’ve noticed a few things:

1 – I’ve had to use the dehumidifier significantly less this winter

2 – Rooms with fewer plants were damper (this is probably because the damp rooms were too cold to put plants in)

3 – Previously damp rooms that I filled with plants were less damp. I used to air dry clothes in the spare room and open the winter to let out the water. The plants now absorb the water so I don’t have to open the window. I measured the humidity with a hygrometer (what a geek) so I have the numbers to prove it.

monstera leaf

How do I check if my house has high humidity?

One sure sign is that you have mold growing – it’s common in older houses, especially in naturally humid rooms like bathrooms and kitchens.

You can get little sensors that will tell you how much light and humidity a room has, as well as the temperature. You can pick them up pretty cheap – I have a link to them on my resources page.

If you already have a dehumidifier (or humidifier), it should tell you on the display how humid your room is.

For reference, the humidity in my house is about 65%. It’s decreased from 75% since getting the plants, but obviously, there could be other factors at play. I’m pretty sure the plants have reduced the humidity though.

hygrometer

What does cause damp?

  • Poor ventilation

This is common in older houses. Make sure you’re airing the house out regularly, ensure that you have an efficient fan in the bathroom and open a few windows (yes, even in winter – if only for a few minutes) to allow air to circulate.

Be aware of anything that can add to the issue, such as drying clothes in the house. Don’t dry clothes on radiators.

By the way, if you suffer from dry air, drying clothes on the radiator is a great way to increase humidity. I’ve started doing this again after years of fearing mold, and my plants love it. No mould. I swear the plants have got rid of it.

By the way, don’t worry unduly if the plants have mold on their soil, it’s rarely anything to worry about.

  • Insufficient heating/insulation

Heating your home will reduce condensation, and the insulation will keep the heat inside.

The biggest cause of damp and mold is poor ventilation and cold rooms. Take your plants out of the bathroom and make sure you open the window after showers to let the moisture out. Bathrooms are cold anyway, plants won’t enjoy it in there in winter.

Since most house plants won’t survive in cold temperatures, they won’t be the problem. As I mentioned before, our dampest rooms don’t have plants in them in winter, because they’re too cold.

  • Water getting in

Leaky gutters or pipework can cause water to leach into your home.

Plants are unlikely to have an impact on this UNLESS you have English Ivy. Ivy can work its way into brickwork, so if you have it on the outside of your house, keep an eye on it.

I know a lot of you will keep English Ivy as a house plant and I….don’t. Not because I think it’ll get into my walls and cause dampness, but because it’s irresistible to pests.

I don’t need the drama.

brushed bronze watering can and pothos marble queen

Can houseplants help with dehumidifying?

Ok, yes they can.

A bit.

From the research, I’ve done, there are plants that like humid conditions and will absorb moisture from the air HOWEVER, these plants will not solve your damp problem overnight.

It’s also worth noting that humidity-loving plants tend to come from tropical climates. Damp tends to be more of a problem when it’s cold, so when you most need your moisture-sucking plants, they’ll not be in the mood for sucking up water.

Sorry.

If you live in a hot, humid, environment though, there are plants you can grow indoors that may make the humidity a little more bearable.

From my experience over the winter, I think house plants definitely do reduce the humidity levels in your house. Like, significantly. But before you run out and buy a load remember that:

  1. If you live in a temperate climate, your bathroom is likely too cold to keep plants in over winter, so if it’s the bathroom that’s damp, plants are unlikely to help.
  2. I have over 100 plants. No wonder they made an impact. I’m just glad they helped, rather than caused more problems.
  3. I am an underwaterer, so the soil is likely to be dry. If you tend to overwater, the damp soil may cause humidity levels to rise.
rhapidophora tetrasperma

Will a dehumidifier hurt house plants?

In my experience, no.

I don’t run my dehumidifier unless the house is cold and damp and needs, you know, dehumidifying. If the atmosphere was dry enough that my plants would suffer, I wouldn’t have the dehumidifier on.

On most dehumidifiers, you can set it so that it shuts off once your desired humidity level is reached. I set mine at around 50% and both my plants and my bathroom walls are happy.

here she is, looking fine

Feel free to water your plants with the dehumidifier water, BUT make sure that it comes up to room temperature first. A dehumidifier is basically a fan, and the water that it sucks in is COLD.

Will the plants enjoy the damp atmosphere?

Plants LOVE high humidity, but only on their own terms.

There are three pillars that make up the PPC (perfect plant conditions):

  • Humidity
  • Warmth
  • Light

Obviously, they need soil and water etc etc, but if you don’t have decent humidity, warmth, and light, you’ll struggle to keep your plants happy.

But here’s the thing: you really need all three to be balanced. If you have great light, high humidity, and warmth, you’re golden. But you only have two, you need to carefully pick your plants so you don’t end up with issues.

The problem with the UK in winter is that we don’t have much light and it’s pretty cold (and none of us can afford to put our heating on). So it’s just humidity, but it’s cold and dark. That’s just a recipe for mold and mildew.

Which plants will absorb water from the air?

I know we’ve already been through this, but I want to make it crystal clear – unless you have a lot of houseplants, they’ll have a negligible effect on the humidity of your home.

You know what would be really useful?

A table of how much moisture each plant absorbs from the room, but I don’t have that data. Perhaps I could conduct an experiment (unlikely though, I wouldn’t even know where to start)

But if you love houseplants and have too humid a home, why not give it some extra help?

pothos and heartleaf philodendrons on mantlepiece

Conclusion: will houseplants make my house damp?

No, not unless a) you have hundreds or b) you chronically overwater them so that the potting medium is always wet.

If you’re an overwaterer, read why that’s a bad thing here. Seriously, read it. Overwatering is the second most common cause of houseplant death.

Many blogs claim that it’s the number one cause of plant death, but SURELY it must be general neglect and being forgotten about.

This winter I may have to experiment with running the dehumidifier, and just making sure to check that my plants aren’t all shrivelling up and dying.

Everyone may have to move downstairs so that I can dehumidify the upstairs.

It’s looking increasingly likely that my living room will feature a fucking massive aloe vera in the middle of the floor.

I could maybe get a table to put him on. Make it look a bit more profesh.

monstera leaf

monstera leaf with text overlay

10 thoughts on “Can house plants cause damp?”

  1. Had a great time reading you!! Living in Central America, I’m trying to get rid of humidity during rain season… Your article is very useful… and hilarious Thanks!!

  2. Loved reading this. I have to thank you for making smile (am sitting in living room, feeling low because of the exteme humidity thats ruining my furniture, picture frames, wardrobe, clothes and boots I could go on and on…oops I have lol) I am having to sand, seal and protect it again n again and its making me friggin, piggin upset!

    My rented place is built into an old wall that is also built under ground, there is a spring/ teeny tiny stream that flows under the place and also happens to be in the spot where the run off from near by cairn drains away (thats hell of a lot of water! Oh and its also in a valley too! But I adore the place and my garden too, , its beautiful and stunning but very bloody HUMID !

    Levels are constantly between (on a good good day) 75) and (on a bad bad day which is quite often) 93 !!!!

    Dehumidifier and ventilation does not touch the sides at all.

    Decided to research planta that could help and found your post. Thinking maybe a big ‘fuck off aloe (sitting in the middle of floor ) and many many other plants might help …even if only to make me feel like I am not living in sometimes cold sometimes hot sauna!

    Thanks for the post and for giving me a boost and stopping me from packing up and finding a normal place to live (which I would despise )
    I’m going to buy me some kick the ass out of humidity plants

  3. Oooo you need Hoya! They like a lot of humidity but hate having wet soil. They’re also not spiky like aloe!

    I’m glad I could make you smile.

    Your house sounds so cool – we can make this work!

  4. How in the world can you say plants soak up the humidity? Have you heard of transpiration? I too have over 100 plants and the moisture level bbn in my home has risen because of it. It has not gotten dryer. I guess what you are saying sort of makes sense that plants draw up the moisture. But how can theny do both?

  5. Why can’t they do both? Human skin can absorb water (though luckily only a bit and only so far into the skin) and release it too.

    Stomata can absorb water as well as expelling it, though they absorb less than they release. It varies from plant to plant too – some plants can absorb more water than others.

    This only considers the biology of the plant though, and when assessing the amount of moisture in you home due to plants you have to consider plant care.

    Factors such as how often you water, what potting mix and pot you use, and the temperature of your home will all affect moisture levels more than the actual plant. Light levels will probably have the biggest effect. People with a lot of moisture loving plants like ferns and calathea with have higher levels of moisture than people with loads of succulents.

  6. You must live in a warm climate. I live in Minnesota and if you have 50% humidity in the house in the winter you windows and walls will be damp with condensation. We have a 2500 sq ft house and my wife has so many plants and this year I can not get the humidly level down below 30%. In Minnesota when it gets below zero if you don’t get the humidity down below 30% you will have condensation on the windows and even in the attic.

  7. I wish! My humidity is about 60%, but there’s no condensation on the walls or windows. It’s not super cold in the UK, it does get below zero in winter, but it’s a fairly temperate climate.

    A fan or some kind of air movement should help – I like to open my windows to let fresh air in regularly (even when it’s really cold), which helps a tonne.

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