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No – it’s just different. Leca is cheaper (over time) and is less likely to attract root rot and pest IF YOU DO IT RIGHT. It’s also a hella learning BUT it’s easier to get leca off the carpet compared to soil.
I’ve recently started transitioning my plants from potting mix to leca, and it’s…been a whole thing.
It’s got one hell of a learning curve and there is so much information out there! I also spent a small fortune on pots and leca and nutrients and all that jazz. I THINK it’s been worth it. Watch this space.
This is the first in what will probably be a whole series on semi-hydro, so I’ll just cover each aspect quickly. This is a blog post, not a dissertation.
If you have any questions please leave a comment below, or message me on Instagram.
What is leca?
Leca is an acronym that should probably be capitalised, but I cba. It stands for lightweight expanded clay aggregate.
So it’s clay that’s been heated. It’s very light (I mean, it’s literally in the name), and it’s porous, so it can absorb water.
Leca is pretty much inert, so whilst it won’t harbour any beasties (fungus gnats begone!), it doesn’t have any nutrients in it. Fertilising is even more necessary than with plants in normal potting mix, and they have to be proper semi-hydro nutrients to boot.
How is growing in leca/semi-hydro different to growing in soil?
You know when you propagate a plant in water and it grows those white roots?
Those are water roots.
When you transfer your plant to soil, you have to keep it moist, and then gradually ease off on the watering, to allow the plant to adapt to its new environment and grow soil roots.
The different types of roots is why plants don’t get root rot if they’re grown in pure water.
In very basic terms water roots don’t like soil, and soil roots don’t like too much water.
The difference between soil and water roots is (I think, but Google wasn’t very forthcoming about it) the way they absorb oxygen. Water roots are also super fuzzy, so don’t panic and think they’re mouldy.
Leca encourages the growth of water roots, although the water level is usually kept below the roots. The leca absorbs water and provides a framework for the roots to cling on to.
Why is leca better than soil?
There are quite a few advantages to using Leca over soil, but it’s not the easiest thing to get started with.
Leca is cheaper than potting mix
Not only do you not need to worry about quality or mixing your own (though there are various types of leca), but you can reuse it.
Boiling leca makes sure than any pests/bacteria are gone and it doesn’t degrade over time.
Don’t run out and buy leca now to try and save some cash though – there is other stuff you need to buy.
You get fewer pests with leca
Fewer, not none.
If you put all your plants in leca, fungus gnats will probably reduce in numbers a lot, if not disappear. Their larvae live in the soil, so they won’t be able to complete their life cycle.
You may get a few errant ones that have come in off other plants, but you’re unlikely to have a real problem.
Thrips are less able to reproduce, but they’re more adaptable than fungus gnats. I personally think they’re easier to eliminate though. It’s also so much easier (and less messy) to shower them too.
You can tip the leca into a tub (I use my washing up bowl), run the entire plant under the tap, and then return the plant to the leca.
Spidermites don’t care about the lack of soil, but they don’t like water. I have a Syngonium trileaf wonder that had baaad spidermites but they disappeared when I switched to leca.
Annoyingly, the plants that have spidermites (Calathea) are notorious for dying during the switch to leca (Calathea? Being picky bitches? Shocking).
Leca makes watering so much easier
The guesswork is gone. Rather than having to work out how wet the soil is, you just have to check whether there’s water at all.
In the beginning, there can be a bit of guessing, such as how far to fill the reservoir and how quickly it needs refilling, but you can set yourself a schedule. That dream of watering your plants weekly/fortnightly can be a reality.
Most plants can be converted to leca
Some are more difficult to transition than others, but apparently, all plants (including succulents) can develop water roots. You can put all your plants in leca if you wish.
This is of particular note to those of you that travel a lot, since you can leave instructions for your house sitter to add, for example, one cup of water to each plant every two weeks. Or to ignore your plants altogether, because you can fill them all up before you go, knowing they’re unlikely to have used all that water in a couple of weeks.
Semi-hydro takes the guesswork out of fertilising
Everything can be done to a schedule – add nutrient water to your plants monthly (or every two months if you’re lazy), top up with normal water, then flush (rinse the pot through with water to remove buildup) and repeat.
You can even skip the whole nutrient thing and use aquarium water.
Leca isn’t as messy as soil
Yes, it falls out of the pot all the damn time, but you can just pick it up. It won’t get ground into your carpet, and your cat is less likely to want to pee in it.
Why is soil better than leca?
It’s easy to get swept up in a new craze, especially one that claims to eliminate both pests am root rot, but the leca life isn’t all rainbows and sunshine.
Transitioning a plant to leca can be a ballache
If you don’t get every scrap of soil of the roots you can end up with root rot, making nutrient water can be a ballache, and there’s a LOT to learn.
Whereas if you buy a plant from the garden centre, you don’t have to do anything. You might not need to repot it for a year or two, and when you do you can just put the whole root ball, soil and all, into a bigger pot and put new soil all around it.
Soil is heavier than l(ightweight)eca
Meaning plants and moss poles stay upright a lot easier.
I’m yet to put any big plants with moss poles into leca, but I’m assuming that you have to wait until you have an established root system before they’ll stand up by themselves.
That being said, you can get smaller, heavier clay balls that may be better for big plants.
Watering is easier
It isn’t difficult to make up nutrient water, but it’s harder than my current routine, which is moving the plant to a waiting tray of water.
Personally I think watering plants in leca is easier if you have a weekly chunk of time to make up the nutrient solution and water all your plants. If you’re more inclined to water a few plants everyday, maybe stick to soil.
Where to buy leca
A lot of people swear by Ikea Leca, but I have a lot of plants and I need a lot of leca.
The first leca I tried wasn’t *quite* the right stuff. My boyfriend bought it for his terrarium, so i thought I’d try my Marble Queen Pothos in it. When I realised it wasn’t ‘proper’ leca i went to remove her, only to discover a load if new water roots. So she stayed in it, and she’s happy (or as happy as can be expected this time of year).
If you don’t do Amazon, there are loads of hydroponics stores on Etsy – this one looks really good and freaking CUTE.
We don’t have many (if any) hydroponics stores in the UK (because weed is still illegal) but they can be a super cheap place to get leca and all the associated accoutrements.
Don’t worry too much about the size and shape of the clay balls – there are pros and cons to big vs small, round vs jagged and I’ve tried all of ’em. The plants don’t seem to care.
Basic equipment needed to get started with hydroponics
I don’t add nutrients until I’ve had my plants in leca for about a month, so you don’t need to get any right at the beginning, but I’ll mention them anyway, in case you’re the kind of person that needs everything before they begin (like moi).
This is what you need:
I like this set of six, but you don’t need special pots for semi-hydro – you just need a pot with holes to put the leca and plant in, and a pot for that pot to sit in, that’ll hold water.
I made the mistake of buying a load of self-watering pots, but they’re not necessary. Instead, you can use all those pots that don’t have holes in (like those white Ikea ones we all have), with a nursery pot inside.
A net pot (that has holes in the sides as well as the bottom) is ideal, but regular nursery pots work perfectly well.
Being able to reuse nursery pots really appeals to my plastic-hating heart. It also means that I can start buying hole-less pots from thrift shops again. Yesss.
Ok, so you don’t NEED this, but if you want to add a reservoir of water straight away (I do, Bebee from YouTube doesn’t) it can really help with transplant shock.
For this reason, it’s great to have on hand anyway, whether you’re working with soil or leca.
That’s all you need.
Nice to have but NOT necessary (at least at first):
- An old toothbrush
Helps get the soil of the roots. Softer is better.
I use these ones from General Hydroponics. Mine are from Amazon, but check out hydroponics stores too.
They seem pricy (and they are) but they’ll last forever. If you can’t afford them atm, your plants will probably manage a good few months without them (results may vary – you know plants).
- Ph stuff
Ok, so you should test the pH of your nutrient solution every time you make up a batch ESPECIALLY if you’re using tap water (which isn’t recommended, but it’s what I use). The pH should be between 5.8 and 6.3.
If your pH is off, it affects your plants ability to absorb nutrients.
You can buy chemicals that can help you adjust the pH:
Americans, either go to the hydroponics store or go to Amazon.
Here in the UK, it costs a freaking fortune to buy from Amazon, so instead head to eBay. I got this set for £14. It’s a different brand but it does the same job for £25 less.
The jury’s out on how important this is – some people claim to never test their pH others say you must do it every time.
I compromise, and sometimes test it.
How to transition plants from potting mix to leca
It’s both simple and difficult to move a plant to leca, and it varies a lot from species to species and specimen to specimen.
I’m going to tell you how i do it, and then leave two videos linked below – one which is the ‘normal’ way to switch plants to leca, and one which is veeeery detailed and is great for learning about troubleshooting.
I love both videos, but I would only use Bebee’s method if something went wrong and my plant started to die. Because it’s very involved and I like methods I can get done quickly.
Measure the leca into the inner pot.
Rinse it through with the garden hose/tap but don’t let it go down the sink.
If you’re indoors, rinse it into a bucket/washing up bowl (which apparently Americans don’t have??) and then chuck it outside. Your drains will thank you
The aim of the exercise is to get the soil off the plants.
I have no patience for this, and do a terrible job. I’m too rough so end up snapping the roots, and I don’t get nearly enough soil off. So far, I haven’t had any casualties.
Get as much soil off with your hands, then blast with a hose/tap (being mindful of those drains) and then go in with a toothbrush if you have the patience.
Step 3 (optional)
Put the plant’s rootball (with the plant still attached) in water. Regular tap water worked fine for me, just make sure it’s at room temp.
I keep my plants in water for week or too, because it allows me to easily get a bit more soil off, whilst giving them a chance to get used to water.
I change the soil regularly 9every 3 days-ish) to increase oxygen absorption (which is compromised by all the soil I left on).
Fill a third of the nursery/net pot with leca. Put in plant. Add in rest of leca.
Try to arrange the plant as best you can, but they can look a bit sad at this point since the leca is too light to hold them in place.
Their roots should help with that soon enough.
A general rule of thumb is that the roots shouldn’t touch the water, so the water should come up to the bottom third of the pot.
This can be a hard to judge, so you can work it out first (by trial, error, and seeing how far the water comes up on the pot) and then scratch a mark on the inside of the cache pot.
I, er, just kind of guess. I suppose if you’re the mathsy type you could worth it out.
I highly recommend these two videos:
They know far more than I do.
My experience with leca
So far, so good.
First, I put some thrips-ridden Philodendron hastatum cuttings in leca, and they’re doing super well (and are thrips-free). New growth points are cropping up everywhere and the roots looks incredible.
I got a begonia cutting a few weeks ago, and that’s now thriving in leca. It’s even freaking BLOOMED.
I actually rooted a cutting of this syngonium trileaf wonder in leca, and it’s doing waaaay better than it was doing in water. And, as I mentioned before, the spidermites have gone. I really couldn’t ask for anything more!
Final thoughts on leca vs. soil
If you’re totally happy with growing your plants in soil, great. You’re not missing out on something spectacular, it’s 100% a preference thing.
Had this not been my job, I probably wouldn’t have tried out leca (oh, and I thought it would save my Thai Constellation, which is still in soil and will remian so for at least another six months).
I am enjoying being able to see my plant’s roots, and I like the reusable nature of leca. This probably isn’t an issue for those of you with a normal amount of plants, but I have a LOT so I go through a lot of potting mix.
Leca was a great choice for me financially, since those nutrients will last me years.
I’m currently experimenting with propagating in leca, so I’ll do an article on whether it’s better than moss/water or whatever when I have a few more props.
Let me know if there’s anything you want me to cover – I’m always open to suggestions.