The Ultimate Guide to Using LECA for House Plants

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It’s taken a while for this guide to put together.

Not the article itself (I mean, it could take a while. I haven’t written it yet. This is only sentence three), but actually learning enough about LECA to produce content that’s actually useful.

A lot of LECA content out there is a bit overwhelming. I distinctly remember spending a fortune on all the stuff I’d need, and then regretting it after watching a few hours of leca YouTube.

I have good news if you’re in the same boat:

  1. A lot of the work involving in transferring plants to leca is done at the beginning.

Once the plants are established, it’s no more time consuming that looking after soil plants, and I actually find maintenance a bit easier

2. You don’t need to get everything straight away

Don’t rush out and buy nutrients if you can’t afford them. Yes, you will need nutrients designed for hydroponic set ups BUT your plants will survive for a few weeks in LECA with no nutrients.

Anyway, let’s crack on.

What is LECA?

LECA stands for lightweight explanded clay aggregate.

It’s little balls of clay that can absorb water.

Whilst you can use leca as a soil additive, it can be used on its own as an alternative substrate to soil.

I have a whole article explaining what leca is here.

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Why use LECA?

A lot of us (including me) get into leca for the wrong reasons.

Those reasons are thrips and spider mites (or lack thereof).

Exceeeept leca won’t stop thrips and spider mites. In fact, it sometimes seems that nothing will stop thrips and spider mites.

Reduces pests

If fungus gnats are the bane of your life, then a switch to leca may save your sanity.

You see, fungus gnats need soil to complete their life cycle PLUS it’s not your plants they like, it’s the soil. They eat the fungus that lives on it. No soil = no gnats.

There have been reports of people seeing gnats after switching all their plants to leca, but it’s pretty rare. You may still see regular flies, but fungus gnats won’t stick around somewhere where they can’t reproduce.

Easier to maintain

If you’re one of those people that just doesn’t quite get over and underwatering, leca may be for you.

It’s also great for people that, for example, have an inflexible one hour slot available in their timetable for plant care and no more.

Less messy

Yes, leca rolls around everywhere and it’s exactly tidy, but you can’t accidentally grind it into your carpet.

Again, there’s a whole post that will outline the pros and cons of leca here.

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Different types of LECA

There are a tonne of different brands out there, and they all seem to vary a bit, which is pretty confusing when you’re starting out.

The first type of leca I used was left over from when my boyfriend bought some to line the terrarium. It was grey and really lumpy and after I’d transferred my first plant (a Marble Queen pothos) I was convinced I’d used the wrong stuff.

It wasn’t round and red like the leca I’d seen on YouTube and a couple of the Amazon reviews seemed to indicate that the stuff I’d used wouldn’t absorb water efficiently.

It was fine. The plant is thriving.

In general, if the product is described as ‘expanded clay’, it’ll probably be ok.

Hydroton is the stuff I use currently. I buy large bags of it, but then I have a lot of plants. The great thing about leca is that once you buy it, that’s it. You can keep reusing it until it wears out (which takes a really freaking long time).

Hydroton is red like traditional leca, and is nicely bumpy. You can but perfectly round leca spheres, but I find that roots adhere best to leca with an uneven surface.

I don’t know if the lumpy leca is actually better for the plant, but it’s definitely better for me. The better the roots stick to the leca, the easier it is flush/rinse plants without leca going everywhere.

A fairly new trend I’ve seen is miniature leca, and it’s cute af. Someone posted a picture on Reddit (that, of course, I now can’t find) of a string of pearls cutting in tiny leca and it was VERY aesthetically pleasing.

If you’re hunting for miniature leca online, be sure to read the reviews and look for comparison pictures so you know you’re getting tiny leca, rather than regular size. Or spend the afternoon picking tiny lecas out of the bag of regular stuff you bought.

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Plants suitable for transferring to LECA

I can’t think of any plants that couldn’t be transferred to leca.

Even succulents and cacti can thrive in leca, though their care is different.

I highly recommend starting with cuttings when you’re just getting started, because you don’t need to worry about getting the roots scrupulously clean or anything like that.

Once you’re in a routine with your nutrients and flush days etc, then you can start transferring trickier plants.

I have an article on which plants are easier/harder to transfer here.

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How do you grow plants in LECA?

Pots/cachepots

You’ll need net pots or nursery pots to hold the plants and the leca. Then you set the whole thing in a pot without drainage holes, and this pot will hold the water.

I bought 50 net pots from AliExpress, and used a small drinking glass as the cache pot. The cachepot doesn’t have to be clear – clear means you can see the roots, but it can also lead to algae growing, so just use whatever you have.

Another option is to just use one pot, but drill a drainage hole in the side.

Why the side?

Well, you still need somewhere for the water reservoir to go, so drill a hole about a third of the way up the side of the pot.

I personally don’t like this method, because it makes flushing bit of a pain BUT it makes watering quite easy, since you don’t need to guess where to fill the water to – just fill to the hole.

If you know about the whole soil roots vs water roots debacle you can skip this section. Otherwise, read on.

Soil roots vs water roots

If you grow a plant in soil, it will grow soil roots.

Soil roots absorb oxygen from the air (overwatering reduces aeration in the soil, leading to root rot). So far, so straightforward.

But when you propagate a cutting in water, the plant grows water roots, which absorb oxygen from the water (like gills on a fish).

If you don’t change the water regularly, the oxygen in the water will deplete, and your plant could get root rot.

When you switch a plant to leca, there will be a period of transition where your plant will need to shed its soil roots and grow water roots.

Sometimes plants look like crap during this period. They’re going through a big change after all.

Keep an eye on the roots, and chop any that are soft and mushy. If you notice a lot of mushy roots, bath them in a mix of two parts water, 1 part hydrogen peroxide.

Washing the roots

This is the bit of leca life that I struggle with most.

Soil can harbour bacteria that promotes root rot AND can impede oxygen absorption. Therefore, we need to get as much soil of the roots as possible, without damaging them.

As I said, I’m crap at this. I’m quite rough and very impatient.

In my experience, roots don’t have to be pristinely clean. I clean the roots until I feel like I’m doing more harm that good (i.e. when I’m removing more roots than I’m cleaning) and then stop.

If you’re really concerned that you haven’t got the roots clean enough, then you might want to consider an intermediary period where you keep the plant in straight water. Change the water daily and rinse the roots. The soil will gradually start to loosen.

Shower method vs reservoir method

There’s a lot of questions about the shower method vs the reservoir method in the various Facebook groups I’m in, and it’s pretty simple.

The shower method is basically like watering your soil plants. You pour water over the leca (saturating as much of it as you can) until it runs out the bottom, and repeat when your plant looks thirsty.

I’m not a fan of the shower method and only use it when I don’t have a cache pot

Nutrients

I use the General Hydroponics three part nutrient system, but that’s only because that’s what everyone was using. If I were to buy nutrients now, I’d probably go a one and done nutrient like Dynagro.

Flushing

You’ll need to flush your leca plants regularly.

Ideally, we’re looking at flushing every month or so, but I usually wait two or three months because lazy.

We need to flush leca because mineral and nutrient deposits can build up on the leca balls and that can affect the way nutrients are absorbed.

To flush my plants, I just run the whole plant under the kitchen tap for a few seconds. That’s it. Try to get the water to hit as much of the leca as you can.

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Can you mix LECA with soil?

I personally don’t, but it could be a cheaper alternative to something like perlite or pumice.

As I mentioned before, plants need aeration in the soil, and overwatering can cause compaction of the soil and reduce aeration.

If you add a medium like leca to soil, it can absorb excess water and increase aeration.

As for ratios of soil to leca, I can’t imagine that it would matter. Since 100% soil works and 100% leca works, then find a solution that fits you (i.e. just mix together what you have).

Just bear in mind that using a soil/leca mix would still mean the plant is growing soil roots (I have no idea at what ratio the plant would start producing water roots – I’m guessing pretty high), so adding leca to soil won’t aid with transferring plants to 100% leca.

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Can you propagate in LECA?

Yes, in fact propagating plant cuttings in leca is my new second favorite way to propagate plants (top is my Aerogarden – if you want to prop hoya, using an Aerogarden is the future).

Propagating in leca is super easy – fill a receptacle with leca, add water (I like to fill it with water, but the level doesn’t matter much in my experience), stick your prop in, and you’re done.

So normally with leca plants you wouldn’t have the roots sitting in the water but it doesn’t matter so much with propagations. For a start, it won’t have any roots yet,so you don’t need to worry about root rot. When the roots do come in, they’ll be water roots, and therefore be quite happy to be submerged.

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How to prepare LECA for plants

Everyone seems to have their preference for preparing leca. Some people put it in the oven, others boil it on the stove, but most of us just wash it.

It’s important that you DON’T wash your leca over the sink. The clay dust can seriously play havoc with your plumbing.

I put mine in a colander and rinse it outside with the garden hose. In winter when it’s too grim to go outside, I do use the sink, but make sure the dirty water is caught in my washing up bowl.

The dirty water is then tossed outside. It usually freezes into a lethal patch of ice outside the back door, and yet I NEVER LEARN.

If you’re reusing leca, you may feel like you want to boil it (or pour boiling water over it) to get rid of any bugs, and it won’t hurt the leca, so go for it if you want to.

BUT

Leca is inert. It doesn’t contain any nutrients. Any pests will die or move onto another plant. Spider mites won’t start colonising leca unless there’s a plant there. Sure, the odd egg may drop onto the leca, so running it under boiling water MIGHT be a useful extra step, but it’s not necessary to do more than give leca a good rinse.

What I’m saying is whilst there is a small chance that bugs could remain in leca, it’s nowhere near as hospitable an environment for them as soil is.

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How to prepare plants for LECA

If you’re a leca newbie and you want to give it a go but don’t want to kill any of your plants, then go the propagation route. Take a cutting of a plant – any plant, but I recommend heartleaf philodendrons.

My Marble Queen pothos transferred well, but I see a lot of people struggling with Pothos online, so I thought I’d just mention than before you go and hack your pothos to pieces.

Stay away from anything that won’t tolerate a little bit of overwatering (i.e. alocasia or succulents).

Once you’ve selected your plant, you’ll need to clean the roots (unless you’ve gone the cutting method).

I’m not fastidious about this. I just remove as much of the soil as I can with my hands, then run the kitchen tap over the roots, getting the pressure to do the hard work. I catch the water in my washing up bowl (again, soil + plumbing = disaster), and once the bowl is full of water, I use my fingers to tease excess soil off.

That’s all I do.

You can get to work with a soft toothbrush, but I found that it did more harm than good.

In summer, a blast with the garden hose works really well.

There is ALWAYS a bit of soil remaining on my plant’s roots when I transfer them to leca. Sometimes there’s quite a lot. Just do your best. You can always take it out of the pot and have another go at cleaning the roots later.

Once the plant is clean, it’s ready to go into leca.

There’s a lot of debate about wet vs dry leca. A lot of people claim that using wet leca encourages root rot, though I always use wet leca (I cba to wait for it to dry) and have never had an issue.

Fill your net/nursery pot a third full with leca, put in the plant, and hold it upright whilst you backfill the rest of the pot. Tap the pot firmly on…something (I use the countertop) to knock out any big air pockets and you’re done!

Don’t add nutrients to the water straight away – the plant won’t be able to absorb them properly using it’s soil roots so at best it’s a waste of nutrients and at worst you could damage your plant.

If you’re using a reservoir (I always do, but if you’re worried about root rot or transferring a plant that likes to dry out a tonne – like a succulent – just water it normally and leave the reservoir empty), add water to just below where the roots sit in the leca – so about a third of the way up.

If the roots sit in the water, they might rot.

You can add Superthrive to help root grow. Superthrive is a vitamin solution that promotes growth but it isn’t a replacement for actual hydroponic nutrients.

I know that that makes no sense (think of it as being like a B12 supplement – necessary, but also not enough to live on) but just trust me on this.

Superthrive can help plants transition from soil to water roots, but it’s not sufficient to feed the plant on its own.

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How often do you water a plant in LECA?

Well, this is the beauty of leca.

Imagine that you’re a very busy and important person that only has an hour or so on a Sunday afternoon to care for her plants.

If you water your soil plants on a weekly basis, you’re probably doing them a disservice.

Plants go through water at varying rates depending on a variety of factors (time of year, temperature, humidity, whether they’re producing a new leaf, etc etc).

A plant that needs watering every couple of days in summer may need watering monthly in winter.

Don’t even get me started on Alocasia. Don’t need watering for weeks on end, then they decide to put out a new leaf (without telling anyone!!) and are bone dry and crispy overnight. Truly the avocados of the plant world.

Anyway.

With plants in leca, you can water them whenever you have time. If you’re really organised, you can mark a line of the inside of the cachepot where the water level should ideally be (a third of the way up, for anyone that wasn’t listening).

When you get the chance to water, make up some nutrient solution (it doesn’t take long once you know what you’re doing) then just go around all your plants and top up the reservoir to the line (or where you think it should be).

And you’re done. You can water and fertilise all your plants at once and be done. Easy.

Obviously this benefit isn’t so good when it comes to using the shower method (hence why I don’t use it). We’re back to looking at how sad and thirsty the plant looks, and watering it then.

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How to fertilise a LECA plant

How often you add nutrient water to leca plants is up to you BUT I prefer to add nutrient water monthly and top up with regular tap water until it’s flush day.

Some people only use nutrient water, but they’re probably more diligent about flushing their plants than I am.

When it comes to preparing nutrient water, there are a few rules that you should follow, and some that are more like guidelines.*

*I am privileged to have great tap water though.

I’m going to go through the steps of mixing nutrient water using the General Hydroponics 3-step nutrient solution because it’s popular and that’s what I have. Also, it’s probably the most complicated system for amateurs that you’ll come across.

general hydroponics 3 step flora series for leca

Step one is to have a big bottle of water. I bought a 5-litre bottle of water that i just refill with tap water now.

I refuse to use filtered or distilled water when I have perfectly good tap water. I could use rainwater, but I save that for my plants in soil.

Also I’d have to run it through a sieve or something because my rainwater buckets are usually full of feathers from birds taking baths.

So you need to start with a bottle of water. You need to add nutrients to the water individually – you can’t mix them all up together and add them water, because er, they won’t work. It casues nutrient lockout, where all the nutrients compete, and some end up locked inside other nutrents and can’t get out to feed your plants.

You need to add FloraMicro (the dark purple one) to the water first. I don’t know why, but that’s what they say. Be sure to shake the solution in between adding each nutrient.

When I’m making up nutrient solutions, I use the ratios that they suggest for plants that are growing. If you have smaller plants, you could use less, but I use these quantities for everything. I’ll update if I have an disasters, but so far, so good (and it’s been a year).

Quantities of nutrient per litre:

FloraMicro – 1.8ml/l

FloraGrow – 1.2ml/l

FloraBloom – 0.6ml/l

The quantities are on the box but they also have the amount for soil too, so make sure you pick for hydroponics.

Embarrassingly enough, I hadn’t realised that you could use these nutrients on soil plants. Why do I have multiple fertilisers? Am idiot.

pH testing

The last step of making nutrient solution is testing the pH, and it’s this that I found a bit overwhelming when i first started on the leca journey.

I am a plant person, not a scientist.

If you also find the whole pH thing overwhelming, skip it. At least for now. We can come back to it later.

When you are ready, you’ll need a pH Up & Down kit. Make sure you get one with a test kit.

ph up and down for leca

When you’ve made up your nutrient solution, you need to test it. This usually involves sucking up a bit of water into a string and popping it into a little vial. Then add in a couple of drops of the testing solution and match the colour you have with the colour chart provided.

We’re looking for a pH of between around 6 and 7. If it’s over 8 nutrient lockout can happen and under 5…well, they’re basically sat in a vat of acid aren’t they?

As well as the ph test kit, you get a bottle of pH Up (which increase the pH) and pH down (I won’t insult your intelligence by telling you what that does).

I have never had to use mine. Ever. My pH has always been fine. Do with that information what you will.

So now that you have your nutrient solution, just fill your cachepots with it.

Ideally, we’d be looking to put a couple of hours aside (depending on how many plants you have) every month.

First you’d flush all your plants through with plain water, then you’d clean all your cachepots, replace the plants and fill up the reservoir with nutrient solution.

Hell, this would even be the ideal time to clean all the leaves.

That’s the ideal scenario.

Realistically, I make nutrient solution when I can be bothered (usually monthly) and when it looks like reservoirs are low.

Flushing is more of an every-other-month thing.

Cleaning leaves happens usually happens separately from other plant care when I’m deep cleaning the rest of my house, or if I fancy giving everyone a shower.

Cleaning cachepots happens sporadically, usually when I’m watering and come across a particularly gross one.

Clear/white cachepots look amazing but get gross super quickly.

You have been warned.

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Can you reuse LECA?

Yaaaaassssss it’s one of the reason I love it so much.

Now, I reuse soil. A lot. And I shouldn’t, but I do. I mean, what’s the worst that can happen? I get thrips? JOKES ON YOU THRIPS, I ALREADY HAVE THEM. BUT NOW YOU’RE GONNA SPEND YOUR TIME FIGHTING AND LEAVE MY PLANTS ALONE.

I joke, thrips don’t fight. That I’m aware of.

Whilst it’s not a great idea to reuse soil, it makes me feel better to do so. I leave it for a few weeks so all the thrips and spider mites can die or move on (I dgaf about gnats, bring ’em on) and then mix in some worm castings for nutrition.

Am I recommending you do this? No.

But have i ever had an infestation/issues from reusing soil? Also no.

If you have, feel free to leave a comment. Just because I’ve never had reusing soil bite me in the ass doesn’t mean other people haven’t.

But yeah, you can reuse leca. As I mentioned before, give it a wash, run it under boiling water if you’d like, and use it again.

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Equipment needed to get started with LECA

Pots

If you have nursery pots (those plastic pots that plants come in), they’re perfect to use as net pots. If you’re using clear pots and have a certain aesthetic in mind, then you can buy net pots BUT they get quite pricey.

They’re also hard to get in large sizes, but you if you look for pond plant pots, you may find something suitable.

When it comes to cachepots, you can use any pot that doesn’t have a hole in the bottom. Second hand shops, old mugs and bowls, yoghurt pots…whatever.

If you’re doing this in a commercial-ish way (i.e. dgaf what it looks like) you can set multiple nursery pots in one big tray of water and use one cachepot for a tonne of plants.

You can use self-watering pots, but you don’t need to. I have these from Amazon, and I like them, but they’re a bugger for algae buildup. They’re cheap though, and look ok.

Here’s my Philodendron Hastatum in one of them:

philodendron hastatum in leca

Superthrive – if you’re short on cash, you can definitely opt out of using Superthrive but it’s handy to have. Adding a little to new transfer can really help them to acclimatise.

Nutrients – I use the General Hydroponics Flora series and whilst it’s not cheap, it will last for long time, depending on how many plants you have. I’ve had mine for a year and have used about 7/8s of the (litre) bottles.

Leca – I use Hydroton, but use whatever you can find. Local hydroponics stores (that I’m yet to find in the UK) are rumoured to get it cheapest.

pH test kit – I’ve linked to the General Hydroponics one, because it’s what the professionals recommend, but here in the UK it’s really expensive. You can get a different brand to pH Up and Down which is much cheaper – I think about £15.

Controversially, I don’t think you NEED pH up and down. I can say that, because I use tap water and pH has NEVER needed adjusting.

So before you splash your cash, see if you can test the pH of your solution through other means (you may need to buy strips but also some pet stores will test it for you for free). If your pH is good, maybe hold off on buying some up and down.

I’m not saying that this is best practice, I’m just saying that you don’t need to go out and drop hundreds of pounds on equipment in one fell swoop.

I don’t want people to feel as overwhelmed by leca as I did when I first started (she says, on word 4,086 of her article on how easy leca can be).

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Leca and house plant pests

I treat my plants in both soil and leca the same way when it comes to pests. I’m a big fan of using plain water to get rid of pests, relying on the power of the showerhead and consistency (honestly, it works, even if it is a bit of a ballache).

(I did actually make up some bug spray the other day soI do use more traditional methods, but when it comes to pests, consistency is usually where people fall down).

Whilst this can be a pain for soil plants, since I have to ensure that the stream of water from the shower doesn’t saturate the soil, it’s great for leca plants.

If you want to run the water through the leca, fine. If you want to take the plant out of the leca and submerge the whole thing in water (my preferred method for getting rid of aphids), the plants won’t mind.

Or it’ll mind a bit, but not as much as if it were in water.

When I’m cleaning my plants, I do like to spray them with neem oil as a preventative measure, and I’ve not seen any issues with doing this to the leca plants.

Adding moss poles to LECA

The one thing that does really annoy me about leca is how hard it is to get anything like a moss pole to stay upright in it.

Unless I’ve missed a really obvious solution, there are only pretty permanent ways to solve this issue. Such as gluing the moss pole to the bottom of the pot. And then you’re likely to end up with it rotting.

I mean, you could attach a moss pole of plank to the outside of the pot, but that is a difficult thing to style well.

I do want to transfer my big Monstera to leca, but it needs support and I haven’t thought of a solution better than ‘lean it against a plant of wood that is in turn leaning against the wall’ and that would be a pain in the arse when it came to flushing time.

As it stands, leca is only for small plants. I have found that plants grown in leca are sturdier than plants grown in soil. My Philodendron hastatum was grown from a wet stick in leca and it’s waaaaay sturdier than the mother was when she was the same size.

If anyone has any solutions to helping plants climb in leca, please let me know.

Similarly, if there’s an aspect of leca care that I haven’t covered, let me know and I’ll update.

Final thoughts

I like leca, but it’s not something you need to do. It’s not like it’s an upgrade from soil – it’s just different. Find out what suits you and do that.

I have a vlog up on my YouTube channel which shows me making up nutrient solution (and bug spray) so if you’re unsure, I go through it all there.

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