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I wish I could tell you that you could set yourself a reminder and water all your plants weekly.
Unfortunately, it’s not the best way to do it, unless you want to overwater.
And you definitely don’t want to overwater.
Read why in this post (tl;dr – it’ll kill your plant babies).
So, how often should you water your indoor plants?
In a nutshell, when they need it – usually between a week and a fortnight BUT IT VARIES MASSIVELY. The only way to guarantee an easy, regular watering schedule is to only keep one type of plant, all the same size in the same type of container and in similar light conditions.
Factors that affect how often you need to water your house plants:
- how you water them
- The species of plant
- How much humidity the plant is getting
- How much light the plant is getting
- The type of pot it’s in
- The type of potting mix it’s in
- The time of year
What affects how often you should water your indoor plants?
So many different factors affect how often houseplants should be watered. The more extensive and varied your collection is, the more time you’ll have to spend checking your plants.
How you water them
If you’re wandering around your house, watering can in hand, sprinkling any thirsty-looking plants, then you’ll probably have to water them more often than if you were taking them to the sink (or bath, if you want to do a load in one go) and thoroughly soaking them until water is running through the drainage holes (which are imperative – read why here).
I’m definitely not trying to sway you in either direction – I’m as likely to just give my plants a little drink as a full-on bath, just be aware that the less water you give a plant at a time, the more frequently it’ll need watering.
I would say that the bath method does require more time (it can take up to an hour – more if I’m leaving them to soak the water from the bottom up, so if you’re pressed for time, a little sprinkle is better than nothing at all.
The plant species you have dictates how often you water them
Some plants are thirstier than others.
There are various reasons for this, the main one (I think – I’ve very much an amateur with access to Google) being how much water a plant can store.
Plants evolve different water holding capacities depending on their natural habitat.
Cacti, succulents etc. can store an awful lot of water in their leaves and stems, and therefore don’t need watering as often as a plant with more delicate leaves.
Some plants have rhizomes, in which they can store water.
A rhizome is (basically) a stem than travels below the ground and sends out roots and root nodes. I would say that the most common indoor plant that has rhizomes is the ZZ plant – if you have one, check its base – you might be able to see a rhizome sticking out about the surface, looking a bit like a potato x carrot.
As you probably already guessed, plants with rhizomes are less susceptible to drought than plants without them.
A lot of house plants come from tropical rainforests, which is why they appreciate a lot of humidity.
Plants that live on the ground, like calathea, evolved to live in constantly damp soil, so they can’t store much water – it would never have been evolutionarily beneficial.
Calathea never considered that humans would want to keep them in their homes.
It’s also worth noting that the age of the plant, as well as the species, can affect how much water it needs. My baby spider plants are always thirsty, but my two big ones often don’t need watering more than once a month.
The level of humidity affects how often you water your plants
First of all, I don’t want to hear anything about misting. I have a whole post on why it’s largely pointless here.
Pebble trays are also not great if you have a lot of plants.
If you have plants that require high humidity, you really need a humidifier. Its the only way to get consistent moisture to your plant.
High humidity will decrease the amount you water your plants, especially if you have a lot of terracotta pots. Basically the soil won’t dry out as quickly.
That being said, watering is not a substitute for high humidity and vice versa.
Why humidity is important to some plants
A lot of aroids (like Monstera and Philodendron) are semi-epiphytic.
They don’t always grow with their roots in the soil. In order to get enough moisture, they’ve evolved roots and leaves that can absorb water from the air.
Calathea are epiphytic at all, they’re just picky.
The amount of light a plant has affects how often it needs to be watered
Light makes plants grow quickly. They absorb it and use it to photosynthesise and create energy.
It stands to reason to a plant that growing quickly will use more water than one that isn’t. That’s why plants don’t need a much water in winter than in summer.
In general (this is not a hard and fast rule by any means), plants that live in lower light situations in their natural habitat are less tolerant of drying out.
I say ‘in general’ because the hardiness of the plant has a big impact. Aglaonema and Calathea fit into the same broad niche (chilling on the rainforest floor) so have broadly the same requirements.
As we all know, Calathea will complain more when they don’t get them.
BUT it does mean that we can get hardy plants to THRIVE if we treat them like their finicky counterparts that have similar requirements.
Some pots absorb water, meaning the plants need to be watered more often
If you feel that you’re a little….neglectful when it comes to watering your plants, then stay away from terracotta pots. Terracotta is very porous and wicks moisture away quickly from your plant’s roots.
This is great for plants like cacti that really like a very thorough soak and then to be dried out quite quickly – they really don’t like to get wet feet.
I have a rather impressive collection of black plastic nursery pots from outdoor plants, that I use to repot my indoor plants once they’re outgrown their original pot (be sure to wash them though – we don’t want to encourage any bugs or fungus).
I know they don’t look great, but you can get some beautiful pot covers to disguise them.
The potting medium & whether it’s top-dressed
If your potting medium is high in sand and is designed to drain quickly, then you’ll need to be a more vigilant waterer.
Quick draining mediums tend to be used on plants like succulents that like to completely dry out before watering, so as long as your plant has the correct potting soil, it’ll probably not add to your watering workload
I’ve recently repotted my orchid in some very quick-draining medium (bark chips) because orchids really really really hate having wet feet. They also include their roots in the whole photosynthesis business, so the pot is clear.
I’m extremely excited for blooms.
If your plant’s soil is covered with something – sphagnum moss, sand or gravel, then less water will be able to evaporate from the soil, so your plant won’t need watering as often.
Covering the top layer of soil with sand is also great for reducing fungus flies, so if you have an issue with them, then you can kill two birds with one stone by adding some sand to your pots.
Diatomaceous earth is another fungus gnat-reducing topdressing material.
If you have Calathea and ferns, then you may choose to top dress with sphagnum moss or coco coir to keep moisture in. I’ve found you end up with gnats everywhere though.
Time of year
In the growing season plants, er, grow.
When plants are growing they need more water.
They’ll also need more water when it’s hotter than the tenth circle of hell (as it is when I’m writing this in July).
It may seem like a ballache to stomp around watering when you could be sunbathing but it’s the most rewarding time – all my plants are shooting out leaves (and my hoya may be about to bloom but I don’t want to jinx it so shhhh) so I feel like the least they deserve is a splash of water.
My personal watering schedule
I try to do a Big Water and a couple of Little Waters over the course of the week.
I do the big water on either a Sunday or Monday (my days off) and little waters on Thursdays (work from home day) and Saturdays.
The big water involves me taking the plants to a large plastic tray in the kitchen and pouring rainwater over them with a teapot and soaking the soil thoroughly.
Sometimes I fill the bath and sitting everyone in that will fit. The aloe has to go in their own because they’re v v big.
I leave them for 20-mins to an hour, then pour some water over the top of the soil (just to make sure it’s thoroughly watered) and put them back.
Some plants are excluded from this ritual, because they really don’t like tap water – mainly just the Calathea and the Sundew.
I massively advocate using a moisture metre to ascertain whether or not your plants need watering. Some people stick their finger in the soil, others can tell their plants need water just by their weight, but I prefer a slightly more scientific approach.
Yes, there have been reports of moisture metres being inaccurate, but I don’t think my finger would be a very accurate judge either, so for now, I’m sticking with the probe.
How I water most of my plants (updated)
I tend to water my upstairs plants using tap water from my water glass, because I spend a lot of time in my office and it’s a great way to waste a bit of time. For that reason, all of my upstairs plants are fine with tap water.
The majority of my plants are downstairs and are bottom-watered. I keep a tray of rainwater on the kitchen counter so that it’s always ready to go. I find any dry plants on a morning and leave them to soak.
If the plant is in a large, terracotta pot, I might leave it all day. Smaller plants are left for an hour or so.
Is it better to water too much or too little?
This totally depends on the plant.
I’ve had a spider plant for years that has been chronically overwatered, and sure, he looked sad, but he’s bounced back. On the other hand, I overwatered a maidenhair fern and it died really quickly.
Many factors will determine how much drought or drowning a plant will tolerate, but in my experience I’ve found that younger plants succumb quicker – overwatering will kill far more quickly that drought in the majority of cases.
I’m likely to forget about my plants for weeks at a time. What plants should I get?
I’m just going to give you a list of the plants that I own that don’t need as much watering as others
- Spider plants
As I mentioned before, the little ones are pretty thirsty, but you can pick a big one up for about a tenner, so if you’re a neglectful plant parent, then consider a spider plant.
I have a pothos that I bought about three months ago that I’ve watered once. ONCE. There’s a chance that it was overwatered at the garden centre I bought it from so it’s been drying out, but still.
- Philodendron brasil, micans, scandens -any of the heart-leaf gang
We’re talking once a fortnight here (that’s every two weeks for any non-Brits. Pothos and Philodendron are just very chill plants – they just sit there, in their medium-low light, chucking out new leaves for fun.
I only have one hoya (I think it’s a carnosa tricolor, but it was just labelled ‘hoya’, which is better than a lot of my plants, which came labelled ‘foliage’. Helpful, garden centre people, thanks) and it never wants watering. They don’t like to be overwatered but they also don’t really like drought, but I’ve found that the soil stays really moist.
I’m quite lucky with the position of my hoya though – it’s in a south-facing kitchen window that’s quite heavily textured (like a bathroom window) so it gets bright light but very little direct light, and it’s humid enough without being damp.
I won’t mention the bloom again, because of jinxes, obvs, but eeeeeek.
- ZZ plant
This is for those of you that will forget about your plants for months at a time (though I don’t encourage this behaviour).
ZZ plants have waxy leaves (great for storing water), rhizomes (great for storing water), and don’t mind a medium-low light placement (great for storing water).
They’re definitely the MVP when it comes to water storage. They’re also fast growers, not picky about…anything, and you can pick one up from Sainsbury’s, B&Q and loads of other places for under a tenner.
Are we all sure of when to water our plants?
Water ’em when the soil’s dry – not daily, weekly, or monthly.
Except for Calathea and ferns, which you just shouldn’t get until you can be trusted to be a more trustworthy waterer.
If you’ve already taken the plunge, you shouldn’t let these plants totally dry out, but don’t let them stay too soggy – water them when your moisture meter hits 3 or 4.
Hope this helps!