Potting soil? That’s old news, LECA expandable clay balls are the hot new thing.
Honestly, when it comes to plants I can see why. For technology that sounds like it’s from the stone age, LECA is actually quite handy in the right places.
This soil-less “all-in-one” substrate means you can potentially say goodbye to; muddy re-potting days, a variety of common plant pests, and a host of typical watering problems – to name but a few.
Interested? In this article we’re going to break down exactly what LECA is, and how to use it with houseplants and terrariums alike.
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What is LECA (and Why it Popular All of a Sudden)?
Well, LECA is a sexy acronym for an otherwise un-sexy product.
“Lightweight Expandable Clay Aggregate” to be precise.
Whether you call them LECA beads, hydroton balls, expanded clay balls, hydroleca or hydroponic pebbles; they’re essentially all the same thing.
You can find them here on Etsy!
Essentially, LECA are clay balls that have been expanded (under considerable heat) in a rotary kiln to produce a honeycomb structure with an enormous relative surface area and strength.
Though LECA is now having its time in the limelight, it’s actually over 100 years old. Historically, LECA has been used in more commercial settings as a building material or agricultural aid. These days it’s the darling of the houseplant industry.
Why Use LECA for Plants?
These (not-so modern) marvels of earthy ingenuity are hailed as the new “all-in-one” plant substrate, and honestly there are plenty of reasons to believe it.
LECA is a versatile solution that’ll work with the vast majority of plants. Something that can’t be said of many potting soil or tropical substrate mixes. For more on substrates check out this post, or my Essential Guide to Tropical Terrariums.
Primarily, their key function is down to their absorptive ability. Their highly porous structure allows the clay balls to absorb water and grow to several times their original size.
Meaning, LECA essentially regulates your plants’ watering.
As the clay balls expand and store excess water, the plants can access it directly when they need it. No more overwatering or underwatering!
Plus, due to their unique composition and nature, they come with a host of added benefits.
Advantages of LECA for Plants
#1: It’s eco-friendly – it’s made exclusively from clay (which isn’t exactly endangered) and it’s completely inert and non-toxic.
#2: It’s durable – seriously, this material is even used in construction. If it can support roads, you can be sure it can support your plants and terrariums.
#3: It’s reusable – well you’d hope it would be reusable if it’s as durable as it says it is! Unlike soil, this medium never expires and you can use it as many times as you need with different plants.
#4: It eliminates the risk of any soil-based pests – no soil, no problem. Pests that reproduce in soil (fungus knats I’m looking at you) can’t get a foothold in a LECA medium.
#5: You can see the roots of your plants – you could argue this is an advantage in that you can see any potential disease and such, but I just love the idea of being able to see our plants in all their glory.
Disdvantages of LECA for Plants
#1: Well, LECA has absolutely no nutrients, so you’re going to need a liquid fertiliser if you want your plants to grow at all.
#2: It looks… unique – LECA is not to everyone’s taste aesthetically, and that’s okay.
Where to Buy LECA
LECA is just one name for a range of expanded clay ball products, and honestly it’s readily available these days from plant and vivarium hobbiest stores alike (or you can even find it in IKEA).
Personally, I buy my LECA from Etsy which you can find here.
How to use LECA/Hydroton in Terrariums
In the houseplant world, LECA is primarily a substrate, but it’s not exactly advisable to fill a closed glass terrarium with expandable balls…
However, LECA is great for terrariums for another reason, and that’s as a drainage layer.
When you consider the function of a drainage layer to create space for excess water to drain, LECA has some great advantages over typical materials like river stones or gravel.
First and foremost, the ability to absorb excess water is very useful. It provides a natural buffering capacity but it also stores the water in a more secure way.
The risks of a typical drainage layer (and reasons some make the case that they don’t work) are:
#1: The plant roots can/will eventually make their way down into the reservoir where they can rot.
#2: If the reservoir fills to the top, water will wick back up the substrate.
LECA eliminates both of these risks. It’s a way to capture excess water and only release it when necessary.
- Resist compaction and never rot or break down.
- Be far lighter than any rocks you’ll find.
- Boost ambient humidity.
- Create an ideal environment for bioactive bacteria.
- Happily support plants even if the roots did make it all the way down to the drainage layer.
- That’s why LECA (often labelled as Hydroton) has been a staple in the terrarium/vivarium industry for years.
It’s perfectly fit for purpose.
Over to You
What has your experience been with LECA?
Do you love it or hate it? Let us know in the comments!