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Self-watering plant pots can be AMAZING.
Unfortunately, the name ‘self-watering plant pot’ is a bit of a misnomer.
They don’t simply water themselves. IMAGINE. I’d have a thousand plants, and they’ll all be healthy. Bliss.
But no. The pots don’t wander over to the sink and fill themselves.
It’s one of those things that sounds good in practice, but in our house, you can’t run the taps whilst anyone’s in the shower (unless you want to freeze/scald them), so maybe it’s best that I don’t have to teach a thousand sentient plant pots when they can and can’t fill themselves.
Self watering pots can be an awesome help when it comes to keeping up with your plants, but it’s important to learn how they work, how to use them, and how to adjust the way you use them depending on the plant they’re housing.
What are self-watering plant pots?
As I said, they’re not actually going to water themselves.
You still have to water them.
Why bother, then? I hear you say.
Self-watering plant pots use a reservoir of water, so you don’t need to water them as often.
That’s pretty much it.
There are a couple of different types of self-watering pots. There are some suuuuper simple ones that you can make yourself (I have a video demonstrating how to do so here) or you can spend a bit more and get some fancy pants ones.
I must warn you though, that median-price area is a bit of a minefield when it comes to self-watering plant pots. I’ve tried a few (read about that here) with mixed results.
How do self-watering pots work?
There are two main types of self-watering plant pots: those with a string wicking system and those, er, without.
String-wicking self-watering plant pots consist of an inner and an outer pot. You put the plant in the inner pot (in leca or potting mix – either is fine, depending on the plant*), fill the bottom of the outer pot with water, put the inner pot in the outer pot so that the string dangles in the water and voila, you have a very simple self-watering pot.
The string sucks up water and delivers it to the soil but over a long period of time. It’s like bottom watering but slower.
*I wouldn’t keep plants that require a lot of water and are in leca in a string-wicking system unless they’re pretty small.
I’d just do away with the string and raise the level of the water to a third of the way up the inner pot.
It’d be a great way to keep plants like hoya that can be susceptible to root rot during conversion though.
The fancier type of self-watering plant pot follows basically the same method, but there’s no gap between the water and the potting medium/substrate. Instead, we use a barrier of pon or leca. It absorbs water which then wicks into the soil via capillary action.
Again, it’s basically bottom watering but slower.
To ‘help’ I’ve drawn you a diagram.
Can you believe I bought an Apple Pencil and the Procreate app so I could learn to draw, and THIS is what I came up with FOUR years later? Oh, and my dad is LITERALLY a PROFESSIONAL artist.
It’s embarrassing, and I COULD just take photos, but I wanted to show you a cross-section and I’m not slicing any of my pots up.
Do self-watering plant pots cause root rot?
As we’ve already established (twice), putting plants in self-watering plants pots is like giving them all their very own little self-watering vessel, which begs the question, why don’t they get root rot?
Errr, they definitely can if you’re not careful.
The thing that stops them from automatically overwatering all your plants is the speed at which the water is wicking up through the soil.
The string, or the leca/pon, is the delivery system of water from the reservoir to the soil, but it’s really slow. If the water was in direct contact with the soil it would wick up too quickly and cause the soil to become saturated.
By making sure the water reservoir and the soil we slow down the process, so the soil remains damp, and never actually gets wet (unless you get one of those pain in the arse pots that require you to fill the reservoir by top watering through the soil grr).
To really make sure you aren’t putting your plant at risk of rot, be sure to:
Select the plant and the substrate well.
You might be able to get away with keeping for example a Hoya in denser soil than it would like, but avoid root rot by only watering when it’s dry.
With a self-watering pot, you’d need to make sure the potting mix was really well aerated (remember that root rot usually stems from a lack of oxygen in the soil) and suits the plant.
Also, you don’t NEED to keep the water reservoir full. You can let it empty by itself and then refill it when it’s completely dry.
If you’re unsure how to judge this but want to crack on with self-watering anyway, try with a cheap, hardy plant. A heartleaf Philodendron would be a good choice.
Choose an appropriately sized pot
Too big and you’re asking for root rot. The plant won’t use up all the water in the soil, never mind whatever’s left in the reservoir.
Choose plants that are growing well
Unless you’re 100% your plant is dying because you’re neglecting and underwatering it, don’t try to rescue a dying plant by putting it in a self-watering pot.
It’s good practice to have a quick look at the roots when you’re doing any repotting anyway, so chop off anything mushy whilst you’re there.
Do you put rocks in the bottom of self-watering plant pots?
I guess you could if you wanted to make the reservoir smaller OR stop the pot from blowing away/falling over.
You can’t replace leca or pon with gravel or stones.
The substrate used to create a barrier between the water and the soil has to be able to easily absorb and hold water, otherwise, er, it won’t work.
You’d have to rely on evaporation rather than capillary action and your plants would die of thirst.
Can you use self-watering pots for leca/semi-hydroponics?
I actually like to use the wicking method for my smaller plants in passive hydroponics (we’re not supposed to call it semi-hydro, oops) because it’s like a cross between the regular fill-the-third-of-the-pot-with-leca thing and the shower method.
The shower method is, in short…watering your plants normally rather than using a reservoir – no ta.
The issue I have with using leca with the ever-popular Lechuza pots is that the cheaer ones don’t have an inner pot, they just have a plate at the bottom. This is okay for soil, but it means you can’t flush your plants.
Also, if you’re lazy like me and don’t diligently check your pH, you’re meant to keep the water reservoir pretty clean (a dirty reservoir can change the pH a lot). There’s no easy way to clean the reservoir without moving the pot.
I do have a cheap AliExpress self-watering pot that works perfectly for leca (my Anthurium Clarinervium lives in it) but alas, it’s disappeared from the site. Should have bought 50.
Best indoor plants for self-watering pots
All plants have the potential to thrive in self-watering plant pots, just like all plants can potentially live very happily in leca, BUT there are some that are best left alone until you’re pretty sure you know what you’re doing.
Here are some that I like to put in self-watering:
Mine goes through stages of being suuuper thirsty and other times, not so much. Putting it in self-watering means it can just do it’s own thing and I just keep an eye on the water level.
I have one in self-watering and one in soil, and the one in self-watering is THRIVING. The other one is…fine.
I can’t compare directly because the one in soil gets better light and is variegated. It looks ok but never blooms. Do variegated peace lilies even bloom (yes, they do, I googled it)?
Peace lilies can be picky about water, and it can be a pain when you notice it dropping but you don’t have any filtered water. Tap is fine, but you risk crispy leaf edges.
With self-watering, you can just make sure that you have some water ready when the water gauge is approaching ‘min’.
Not totally foolproof by any means (I treat the water gauge like the petrol gauge – it’s a guideline rather than an actual rule), but better than having to poke the soil every five minutes.
Plants on the floor
Purely because it means you can water them without worrying that the water will leak onto the floor.
Saucers are fine and all but we’ve all been a bit too enthusiastic with the watering, thought it was gonna be fine, and then WHOOOSH water has overflowed the saucer.
Specifically self-watering pots with a water gauge. Again, this is a laziness thing. Rather than having to get a ladder out and check your plants when you think they might be dry, you can just keep an eye on the gauge.
The water gauges are NOT 100% accurate (or even like, 75% accurate) but I have a habit of just sort of forgetting about/abandoning my hanging plants so having a visual reminder that they’re dry is waaaaay better than nothing, however inaccurate.
Advantages of using self-watering plants pots
- You can schedule your watering
No more having to go round and check soil! You can retire the old moisture metre!
This is great if you travel a lot.
I have an article here about what to do if you have plants and you travel a lot and in all honesty, they’ll probs be fine if you’re only away for a couple of weeks BUT if you’re having someone take care of them, it’s so easy to say to them ‘only water them if the water gauge is at ‘min’ or below’.
If you’re a busy person that only has one hour per week (or whatever) in which to take care of their plants, self-watering pots are a great addition.
As well as scheduling watering, you can also make up a lot of nutrient water and fertilise everyone on the same day.
If you’re feeling really nurturing, you can even dump out all the old water, clean the reservoirs and replace with nutrient water.
- No more water leaking on the floor
Depending on how accurate you are with a watering can!
- You can use them for leca or soil
Or mix and match, which is what I do.
- Great for underwaterers
I’m terrible for underwatering my house plants. Unless they visibly wilt I just don’t notice them.
Self-watering pots not only give me something to just glance at and know if they need water, but they also give me longer to remember them, because it takes that bit longer for the plants to actually die.
Problems with using self-watering plant pots
- They’re expensive
Like, not super expensive but more expensive than regular pots.
I kind of wish I’d gotten into self-watering pots when I had, like, twelve plants, but NO I was too besotted with terracotta (it’s so cheap and it all matches!).
You know, before I realised I was subjecting my plants to death by dehydration.
I’m currently building my collection up slowly, but it’s easier for me because I can buy them and then review them for you, so they have a dual purpose.
Although if you’re looking for a sign that you should start a blog, that was it.
- They don’t all work that well
Sometimes it’s clear that the manufacturers haven’t thought through the design, or consulted anyone planty.
The ones with a hole in the bottom (raised on a plinth so the water doesn’t drain out, but still a pain in le bum) are annoying, as are the ones that don’t have a separate tube that you can pour the water into so you don’t saturate the substrate.
- They can cause root rot if you’re not careful
As long as you use an airy substrate and the right sized pot (and assemble everything correctly) you should be fine, but it can happen. Perhaps not something to try on your most prized plants.
Recommendations for self-watering pots
These string wicking ones from T4U are good. I really wish I’d checked the link out first – I could have traced their picture of how the pots worked. Never mind.
I hope that answered all your burning questions about using self-watering pots! Please let me know if there’s anything you want me to cover.