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There are loads of factors that will influence how long a house can survive without water, including:
- The species of plant
- The size of the plant
- The root structure
- The plant’s health
- The substrate it’s in
- The humidity of its surroundings
- How much light the plant is getting
- The temperature of the room
- The time of year
Overwatering is far more common than underwatering for novice house plant caregivers.
Humans tend to like to do their tasks on a schedule, and we also have a ‘more is better’ approach to a lot of things. It’s not at rare for plant newbies to aim to water their plants daily, and then wonder why it’s dead two weeks later.
Some plants, such as succulents can go for MONTHS without a drop of water. Even humidity-loving plants like ferns and calathea can be revived after a couple of months of drought.
The leaves may shrivel up and drop off, but the roots can last a lot longer than the leaves – shedding the leaves allows the roots to conserve more moisture. Just because a plant looks dead, doesn’t mean it can’t be brought back.
There are several factors that will influence how long a plant can go without being watered. If you travel a lot or struggle to remember to water your plants, make sure to pick plants that bounce back from drought easily. Don’t use very well-draining soil, add materials like perlite to hold onto more moisture, and don’t put your plants in very warm spots. There’s definitely a balance to be struck here (you don’t want to accidentally induce root rot!), but there are little tweaks you can make to increase the length of time your house plants can go without water.
The species of plant
This seems obvious to people that have been into plant care for a long time, BUT remember when you were new to the hobby and you just couldn’t resist that cool-looking cactus and the maidenhair fern?
You think to yourself, I can water these every couple of weeks and they’ll thrive!
And they definitely could, if you put your cactus outside in the blazing hot sun, and you keep your maidenhair fern in a terrarium. But if you shove them both on your bookcase with a medium amount of light, then you’ll need to water your fern probably weekly, and the cactus every couple of months.
Also, the repercussions of drought are different for both plants. The cactus will be able to survive for MONTHS without water. Possibly years, depending on its age and various other factors.
The maidenhair fern, on the other hand, will crisp up after a couple of weeks, depending on the humidity in your home. The roots will live for much longer, depending on how dense the soil is – perhaps a couple of months.
The size of the plant
Larger plants can go longer without water than smaller ones. I don’t actually know why this is, but it’s…just one of those things. It could be that they’re more established, and are therefore quicker to respond when there’s a drought.
They do have more roots and a bigger pot (presumably) but pot size increases with root size, so the spare room (as it were) left over in big vs small pots should be the same.
The size of the pot
This is a tricky one, because I don’t want to encourage you to run out and move your plant into the biggest pot you can find, just because you cba to water it.
If you up-pot your plant into a pot that’s too big for it, then you risk overwatering by proxy i.e. the soil is holding on to more water than the plant can use. This can cause root rot-causing bacteria to thrive.
HOWEVER there are some plants that are more resilient to root rot than others, and if you promise not to water too frequently, will do ok in a big pot. Plants like Monstera deliciosa can live quite happily in pots bigger than their roots require. It will concentrate on growing roots over leaves though, so if you think this might be an idea you want to try, buy a Monstera that is already at the size you want.
The origins of the plant
All plants are different. It’s one of the things that makes this hobby frustrating at times. For every Pothos that’s thriving in the cupboard under the stairs, twenty more are dying on an east-facing windowsill.
Some plants have stronger genes than others. Mother plants in nurseries have been specially selected because they’re great at adapting to various conditions.
Plants like oxalis, mint, and Monstera deliciosa are invasive species. They can adapt to many different environments and spread like (as?) weeds. It makes sense that these plants will do better in adverse conditions than those that don’t like it when you exhale near them *cough* Calathea white fusion *cough*.
The root structure
One of the reasons Monstera deliciosa are pretty happy in a bigger pot than usual is that they have very thick, sturdy roots. Plants that have thicker roots typically hold more water in them.
Whilst the roots don’t store water for other parts of the roots, so it won’t help the leaves in times of drought, it does mean that the roots can survive for longer during drought than a plant with thinner roots.
Anthurium clarinerveum is another plant with VERY thick roots, and whilst sygoniums don’t have quick the same root situation, they’re pretty good at staying alive during drought.
My Monstera and Anthuriums have both gone for months at a time (max probably three months) without water. The Monstera got a bit crispy, but she recovered really well.
The plant’s health
A plant being healthy/unhealthy doesn’t literally affect how long a plant can go without needing water, but a plant that’s infested with pests or has insufficient light/humidity will feel the effects of dehydration more than one that’s healthy.
I suppose it does literally affect it then. I just didn’t want to insinuate that a healthy plant can go for longer without water because I don’t want people to think they can neglect their plants without ut having an impact. Anyway.
If, for example, a plant has spider mites and then you neglect it, the plant may just give up. Whereas those two problems are manageable on their own, together they could take out a plant in a few weeks.
The substrate it’s in
This also comes with a warning: don’t put your plant in a very dense soil mix just because you anticipate forgetting to water it.
HOWEVER, you can amend your soil so that it doesn’t dry out TOO quickly. If you’re a chronic underwaterer, then I would use store-bought house plant soil. If you find it’s too dense and you get root rot, then add something like perlite or orchid bark
The humidity of its surroundings
Some plants need high humidity. If they don’t get it, then they can’t photosynthesise properly. I keep all of my humidity-loving plants in a terrarium and it is a GAME CHANGER when it comes to forgetting to water plants.
Not only does the humidity help keep the leaves plumper (dry air can suck moisture out of them), but it also stops the soil from drying out so quickly (for basically the same reason).
If you love maidenhair ferns then a terrarium is definitely the way to go if you’re likely to forget to water but don’t get the fronds wet – they don’t like it at all.
How much light the plant is getting
A plant that gets a tonne of light will dry out a lot quicker than one in a darker spot.
Before you rush off and move your plant away from the window, er, don’t.
Light is one of those factors that has a HUGE impact on the health of your house plant. It will help it grow bigger, and faster, and give it the energy to fight off pests and diseases.
It will also make your plants dry out more quickly than if they weren’t in such bright light. Not only does the heat from the sun dry the soil out, but the light makes the plant grow faster and therefore need more water to grow.
Don’t move your plants permanently out of great light just so you don’t have to water as often, BUT you could move them if, e.g. you were going on holiday/vacation for a few weeks and are worried they’re gonna dry out.
The temperature of the room
The hotter the room, the faster the water will evaporate from the soil. There isn’t much point in adjusting the temperature of a room to suit your plants. I refuse to waste electricity heating a room just for plants, so in winter my plants all move into the rooms that are warmer by default.
Again, don’t try to hack the system by keeping your plants in colder rooms. You could end up with damp and mould, which isn’t great for you or your plants.
The time of year
I’ve put this right at the end because a lot of people get caught up in the whole ‘growing season’ thing, and that isn’t something that’s always relevant. In the wild, tropical plants grow year-round. In my south-facing living room, my plants grow year round.
In my slightly cooler bedroom though, the plants slow down a lot in winter. It’s a bit darker and cooler than the living room, but perfectly fine for plants to be. They don’t decline, but they don’t grow.
I could move all my plants into the living room, but I actually quite like not having to water my plants very often over winter. Some plants, like my jade plant, might not get watered at all from November to March.
Whether to water your plants in winter is something you have to work out for yourself. It depends a lot on where you live, and the light and temperature in your home.
There’s no one right answer when it comes to how long house plants can go without water, but in my experience, they can go a lot longer than you might think. Plants can bounce back from being leafless stems with nothing more than a good soak and a warm sunny windowsill.