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Propagating plants in leca is, in my experience, a little bit easier than propagating in just plain water.
The stem of the plant isn’t sitting in water, so stem rot can be staved off for longer.
It’s not completely rot-proof – the stem will be touching the leca, which will be damp, but it’s not, you know, wet wet.
What is LECA?
Leca are those little clay balls that are all over my office/plant room floor.
As an aside, how fancy does it seem that I have an office/plant room? Pretty damn fancy. In reality it’s my second bedroom (of two, total) that’s big enough for a double bed but LITERALLY nothing else. Perhaps a shoebox-sized night stand.
So leca, or more correctly LECA (I tend not to write it like that because it looks like I’m shouting LECA at you) is an acronym for lightweight expanded clay aggregate.
I’m guessing they heat clay until it pops like popcorn, rather like they do with perlite and vermiculite.
And like perlite and vermiculite, the popping action results in a little ball of clay FULL of holes, all ready to absorb water.
Why is leca good for plants?
If you’ve been hanging around this website for a while (or took a biology class once), you’ll know that plants like oxygen. Like, a lot.
Tbf, who doesn’t?
The reason plants get root rot because we overwater or put them in too dense of a soil is actually lack of oxygen (which can allow root-rot causing bacteria to thrive).
The leca absorbs water, so the plant can grow BUT the gaps between the leca allow for good aeration. Everyone’s happy.
The roots that grow in leca are water roots – the fuzzy white ones that form when you propagate in water – not soil roots, so they’re designed to absorb oxygen from water.
It does get a bit confusing, because then how are they absorbing oxygen from the gaps between the leca? I’ve chosen to believe that, er, they just are. If a botanist can explain this to me, great – plz leave a comment.
All I know is that plants grown in leca grow water roots, so you have to be careful when you put them back into soil.
How to propagate a plant in leca
It’s super easy and straightforward.
Step 1: pick a propagation vessel.
You can absolutely just use whatever you would use to propagate something in water. An old jar or whatever.
Don’t use anything with a narrow neck.
The leca might go into the pot, but it might not come out once it’s clumped together with plant roots. This is important if you, like me, are likely to accidentally abandon your cuttings for weeks.
Pulling the cutting out a narrow-necked bottle could result in you ripping any roots of the plant when you pull it out, because roots tend to stick to leca.
The only problem with using a closed container like a jar is that it’s a pain to change the water with leca going everywhere.
More diligent plant carers will also note that it’s harder to flush propagations.
I personally don’t use nutrients when I’m propagating, so I’m not worried about flushing, but it is a pain if you accidentally fill the reservoir too full and your only option is to tip the water (and all the leca) out.
You can drill a hole a third of the way up the glass, but for me, that’s too much hassle (plus drilling holes in glass is something that requires practice.
You could also use a small nursery pot and cachepot as a propagation vessel – a smaller version of a big leca setup. The only disadvantage here is that it’s more difficult to see the roots without removing the plant from leca.
I like to combine both methods by using a clear net pot (I bought 50 from AliExpress for about £5) and a glass tumbler about the size of a whisky glass.
I can see the roots growing and it’s easy for me to flush the pot and change the reservoir.
Btw, I rarely change out the whole reservoir for propagations, but once the cutting is old enough for nutrients, I dump out any remaining water when I add the nutrient water monthly.
Step 2: take a cutting
The first plant I tried propagating in leca was a Tradescantia, and I highly recommend them to beginners. I personally find that Hoya and Pothos root well in Leca but there are so many horror stories about both on YouTube that I hesitate to recommend them.
Starting with a cutting you don’t mind losing won’t hurt.
Step 3: fill your vessel
Make sure your leca is clean (don’t pour the water you used to clean it down your drains – they won’t like it!), then fill a third of your vessel or inner pot with leca.
Then add your plant, and pack it with leca. Firmly bang your vessel on the counter to knock out any air pockets (the baristas among you will be well-versed in this method).
Step 4: add water
The water should fill a third of the vessel, below the roots. This is sooo much easier to do in either in a clear jar or a clear cachepot.
If I’m using an opaque pot, I must admit that I just guess a third, but whta you should do is add a bit of water, add the inner pot and remove the inner pot to see where the watermark is. Keep going until the watermark is up to a third of the pot. MARK THE OUTER POT.
That way, the next time you can just fill the pre-marked line.
Water displacement is a bitch.
(I was gonna write ‘fuck Archimedes’ there, but it’s not really his fault)
I don’t use nutrient water here, but many people do. I just use tap water or aquarium water.
If you choose to use nutrient water, dilute it to half the amount recommended.
For those of you who use the Flora series (get it here on Amazon), they print the amounts you need for all stages of growth on the side of the bottles:
They also print the amounts you need for soil, so check you’re looking at the water side – I’ve circled where it is on the photo, and highlighted the column you need.
If you only have one small prop and don’t need a litre of nutrient water (and cba to work out how to decrease the volume) make up a litre, and then add more nutrients so you can use the water to fertilise other plants.
For example, you need 0.5ml/l of all three nutrients for propagations. Make up a litre, take out the little bit of water you need, and then add an extra 1ml of Grow and 0.5ml of Micro. You’ve now got a nutrient solution that you can use fertilise your established plants in soil.
(All that info is available on the side of the GH nutrient bottles.
You absolutely can save your nutrient solution for the next time you need it, but I’m not 100% sure how stable the nutrients are in terms of degrading in absorption ability (I’m sure if they exploded or something, General Hydroponics would write that on the bottle in big letters).
It’s not always feasilble to store bottles of nutrients though, so I thought I’d give you options.
Many people swear by adding Superthrive to propagations (leca and water). I do if I remember. Does it make a noticeable difference? Errr not that I’ve noticed, but I’m not very observant.
Superthrive ISN’T a fertiliser; more like a multivitamin. Helpful, but no good on their own. Once your plant has established roots, you’ll need to add hydroponic nutrients if you want to keep it in water/leca.
By the way, don’t worry if the roots accidentally grow into the water. Mine always do, and I’ve never had an issue with root rot.
You can always take the plant out of the pot and either trim the roots or rearrange them so they sit higher in the pot.
Look at my Hoya Krinkle 8’s roots:
Advantages of using leca to propagate
As I mentioned, it’s now my favourite way to propagate (along with propagating in the Aerogarden, which is great but limited to small cuttings).
Let’s be honest – mostly because it’s waaaay more convenient and forgiving than just using water.
Fewer water changes
One of the most important things to remember when propagating house plants in water is to keep on top of water changes.
Some plants are more forgiving than others – Sansevieria propagations, for example, are fairly tolerant of being accidentally left for weeks without changing the water – but regularly (every few days) doing so will result in your cuttings rooting much faster.
This isn’t so much of an issue with leca, since the plant’s roots aren’t actually in the water – the water reservoir is lower than the plant’s stem. The oxygen the roots need comes from the air trapped between the leca.
Less chance of rot
There’s less chance of root rot, due to the abundance of oxygen in the leca, but also, you’re lowering the chance of your cutting rotting in the water.
Not many terrestrial plants enjoy being submerged in water and will rot over time. I imagine it’s like the plant version of trench foot – not good.
Leca is damp, so we can’t 100% rule out the chance of stem rot, but it’s not as wet as, er, water.
Can we all take a minute to acknowledge that weird-ass sentence? Thanks.
More forgiving of being forgotten
This is the biggy for me, and it’s basically due to the two advantages I mentioned before.
The plant isn’t depending on the water reservoir for oxygen, so you can accidentally check to forget the cutting for weeks and it’ll most likely be ok.
Definitely more ok than a water propagation in the same scenario.
Anyone else find it SUPER ANNOYING when water propagations won’t stand up and keep falling over?
It’s ok if you have a long, skinny propagation vessel, but sometimes I only have a little spice jar!
Adding leca just gives it something to anchor onto.
Apparently, though I haven’t tried it yet, Lechuza pon is even better in this regard, because the granules are smaller.
It’s also coated in fertiliser, which is freaking life-changing. Why can’t they do that with perlite?
Disadvantages of using leca to propagate
I’m pretty spontaneous when it comes to taking propagations, BUT I make sure I have a pot full of washed leca at all times, plus I have about 45 clear net pots left.
The only thing I need to lay my hands on that I might not have is a spare glass outer pot.
UK-based folks – I have the solution.
You know those Gu pots that went viral on TikTok because you can turn them into a container with a Pringles lid?
This is going to be very confusing for people who have no idea what I’m talking about.
Anyway, they make a great inner pot for props:
I’m sorry I didn’t wash it, but I’m not one of those bloggers that spends hours on photos – I didn’t even know I was gonig to mention them until, er, I did. So I just grabbed it and took a picture. It’s currently being used as a saucer for my ginger propagation (that just started growing in my cupboard – thanks for the inadvertant plant, Sainsbury’s).
So yeah, it can more hassle to gather your equipment for propagating in leca, unless you’re a cheesecake fiend like me (and it’s hard to find vegan ones, so I always go back to Gu).
Can be messy
This really depends on you as a person. Do you prefer picking up leca, or drying your floors.
I hate doing both, so I personally think water propping and leca propping are equally messy.
BUT NEITHER ARE AS MESSY AS SOIL.
You need a cache pot
True, but I feel we’ve already covered this. Go to the shops. Buy a load of Gu desserts. Eat the desserts. Wash the
cachepot container. Pot aquired.
Which plants propagate well in leca?
I personally think that most plants propagate well in leca.
I would personally recommend staying away from anythign corm-y, like Alocasia, just because, well, they’re picky bastards that love to rot. They do propagate well in leca, but they’re not the best for beginners.
Don’t feel the need to go and buy 50 net pots. only got them because I thoguht they were bigger (and therefore more useful) but they’re pretty small and only good for props, despite being the biggest size.
I would advise just using tiny nursery pots, preferably ones you’ve reused (though you can find tonnes on places like Facebook marketplace). You can cut slits in the sides so you can see the roots poking through.
Try propping in leca if propping in water is bit too hands on for you – I have a much higher success rate with leca that with water, purely because it needs much less babysitting.