What is LECA and How It Can Help Your House Plants

silver pathos growing in a semi-hydroponic system using LECA

Collecting and owning house plants has become very popular over the last few years. Not only do house plants enhance the ambiance of our indoor spaces, they also purify the air, and simply increases our happiness. However, for a new plant parent, learning about plant care can be well… overwhelming. If you’re like me and horticulture does not come natural, let me help you take some the guesswork out caring for your plant babies. LECA (lightweight expandable clay aggregate) is the newest trend in plant growing medium.

Hopefully, by the end of this post you’ll know all the benefits of using LECA to help your house plants thrive.

LECA growing medium in a strainer being rinsed for use

LECA is an acronym actually. It stands for – Lightweight Expanding Clay Aggregate. It is a growing medium, like soil, used to grow plants. These baked clay balls expand when water is added. While leca itself do not provide plants nutrients, there are many benefits to using LECA. 

This material is used instead of traditional potting soil as it addresses some of the problems associated with traditional potted plants. Learn why LECA is becoming so popular and why you may want to convert your houseplants to this planting medium.

What Exactly is LECA?

Lightweight Expanding Clay Agitate  or LECA – was developed in 1917 in Kansas City, Missouri.

LECA is made from baking clay in a rotary kiln. The clay is baked at 2,190ºF (1,200ºC) and form their roundish shape from the constant rotation while baking. During the heating process, gas expands making thousands of honeycomb like holes in the clay. This causes the clay to be more lightweight when compared to regular soil. 

Since LECA is porous, the clay pebbles absorb water causing them to expand, which also aids in provides water to the root system of your plants. Now this medium will not provide nutrients for your plants, but more on this later.

clay LECA pebbles

What Makes LECA the Perfect Growing Medium?

LECA makes for a superlative growing medium for most house plants. It’s odorless, eco-friendly, and reusable for starters. 

These little clay pebbles can completely takes the guesswork out of when to water plants. 

Overwatering can be the main cause in plant loss for many plant owners. When a plant gets too much water the soil decomposes and compacts on the plants root system. In addition, waterlogged soil deprives the roots of oxygen and causes the root system to fail. Growing plants in LECA eliminates this common plant care mistake.

This is just one of the reasons to use LECA to help take the guesswork out of caring for your house plants.

Here are some of the most important benefits of using LECA as a growing medium:

  1. It’s an extremely porous medium – this means plenty of oxygen can get to the roots of your plants. Lack of oxygen causes root decay and disease which is often the cause of plant loss, especially in indoor plants. 
  2. I does not degrade – unlike other growing mediums, LECA does not decompose or compact over time. Soil compaction causes increased chance for root rot and disease. Because it does not decompose, it’s nutrient system and araitation quality does not change over time – this eliminates the need to repot your plants. 
  3. It’s cost effective in the long run – it is reusable. Plain and simple, you never need to buy more. You won’t need to remember the last time you changed the soil or buy more yearly, saving you money in the long run.
  4. It’s environmentally friendly – LECA can be rinsed and reused as many times as you like. They are safe to dispose of and have no negative impact on the environment unlike potting soil mixtures that typically contain synthetic fertilizers non-degradable material (perlite for example.) 
  5. Allows you to monitor the root system –  using LECA allows you to visually monitor the growing roots of your plant. This will prevent impaction of your plants root, and lets you know when it’s time to upgrade your pot size. It also allows you to monitor for possible disease.
  6. Inhospitable to bugs – due to the neutral pH and space between the large aggregate this medium is completely undesirable to pests. This prevents infestation of your plants unlike all other growing mediums.
  7. Allergy free – LECA is a sterile medium, meaning it does not hold mold and bacteria. This means people with sensitive allergies can finally grow house plants.
  8. Capillary Properties – is unique to LECA due to the fact that the clay draws up water and nutrients from a lower reservoir, supplying the root systems. This helps you from overwatering and flooding your plants.

Are you noticing the trend here? The key too healthy plants is all about having a healthy root system! The easier it is to monitor and tend to your plants root system, the healthier your plants will be. 

LECA allows for optimal conditions to provide you with a healthy, happy plant

beautiful fuzzy and healthy new roots on a plant cutting grown in LECA

Some Drawbacks of Using LECA?

It wouldn’t be fair if I didn’t discuss some possible drawback of using this medium as well. It’s important to know all the pros and cons when considering changing your plants growing medium.

Let’s discuss possible cons of using LECA before you consider taking the plunge.

  1. Can be costly in large scale – depending on how large your plant collection is, large quantities of LECA can be costly in the beginning. However, LECA is reusable so in the long run the cost upfront evens out.
  2. Not suitable for cold climates – since the clay is porous, frozen water can get into the small channels making it more susceptible for fracturing and compaction of the substrate. Additionally, due to its arriation LECA provides very little insulation to your plants root system.
  3. Poor water holding capacity – these clay pebbles drain wonderfully, however without a consistent watering system it can cause your plants to dry out. This is where semi-hydroponic systems are utilized (see more below.)
a very close up look at porous clay LECA

What does semi-hydroponics mean?

Oh gosh, this could be another entire post all in itself!

Semi-hydroponics or “semi-hydro” (and sometimes referred to as hydroculture), is a technique where plants are grown in an inorganic medium that does not decompose. The term “semi” comes from the use of non biodegradable material (usually LECA) to hold the plants root system in place, unlike pure hydroponics where the plant is suspended in just water.

Semi-hydroponics is also known as “passive hydroponics” due to using capillary action or a “wicking” action to draw the water rather than a pump. The growing medium draws water upwards towards the root system of the plant providing the plants root system with a constant nutrient and water supply.

 

a plant being grown in LECA clay pebbles

Where do you buy LECA?

This lightweight growing medium has become popular enough that it is easily found in most local garden centers such as Home Depot, Lowe’s and Walmart. 

Personally, I find it easier to purchase online and have it delivered in the quantity needed without the fuss and mess. I use two brands mainly – GROW!T and Hydroton. Both come with relative consistency in shape and size. I have not noticed a difference in my plants using any specific brand of LECA. Mostly you’ll notice a change in shape, size and color consistency.

I will say one of the best kept secret is purchasing LECA from IKEA. Yup, you heard me. I recently found at my local IKEA they are selling 5.3 quart bags for $5.99 (compared to Hydroton 10L for $13.99.) You save a little here, a few bucks, but if you frequent IKEA it’s worth picking up. Don’t make a special trip- also, not all IKEAs are carrying LECA.

Frequently Asked Questions

Most plants will do well in LECA. Some commonly successful species are:

  • Orchids
  • Philodendrons
  • Hoyas
  • Pileas
  • Monsteras
  • Peperomia
  • Anthuriums
  • Alocostias
  • ZZ Plants
  • ALL Pathos – they love wet roots!
I honestly haven’t found a plant that doesn’t like semi-hydroponics. Now some like to dry out more than others, and some do not like to have their roots sitting in water – some do. Know what your plants prefer and do your research, but most of all don’t be afraid to transition your plants to LECA!

When you first get your LECA, you’ll need to rinse them. LECA comes with a fair amount of particle dust so you’ll want to rinse this off before using.

To do this, use a colander (designated for your LECA), rinse and rotate the clay pebbles until the water runs clear. 

If you’re intending to reuse your LECA, it’s best to boil them. This will kill any algae or bacteria that can transfer from plant to plant. I boil mine and store them in a large container until I need them again.

You should only water your plants when the LECA is no longer in contact with the water reservoir. Checking in with your plants occasionally will help monitor levels.

I tend to change my water every two weeks. This helps me ensure my plants are receiving enough nutrients. However, the size of pot, type of plant, humidity in the house and time of year all can influence watering. Just keep those things in mind.

I believe price volume it is slightly more expensive (depending on what soil your comparing it to.) The reward is once you purchase LECA, you no longer have to buy more – unlike soil – because it doesn’t decompose.

The expense is in the set up of semi-hydroponic systems. You’ll need net pots and catch pots – so two pots per plant. This can get pricey, especially if you are repotting large plants. I recommend using net pots for plants needing <4″ pots. Switch to nursery pots, and just drill yourself some extra holes, for plants needing pots > 6″. It will cut your costs in half and work perfectly well.

Yes. You need to supply your plants nutrients when watering. The best fertilizers to use are those designed for hydroponics. I recommend Flora Grow and have seen great results when using it. I also recommend SUPERthrive in your water changes and when rooting plants in LECA.

Truthfully, no brand is more superior than another. I purchase mine online (due to convenience) and I typically order Hydroton in 10L bags.

However, if I’m being honest, the cheapest LECA I’ve found is from IKEA. That’s the best price on the market I’ve found for quality and quantity. 

Happy growing plant friends!

XOXO,

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4 thoughts on “What is LECA and How It Can Help Your House Plants”

  1. Super helpful! Thank you. One question, how exactly do you use “SUPERthrive in your water changes and when rooting plants in LECA.”. Do you soak the leca in it?

    1. Jennifer,

      Great question. I add a little superthrive in a watering can and then fill. A cap full goes a long way! Once every other watering is plenty.

      Happy growing!

      XOXO,

      Maria

  2. Pingback: Advantages of using LECA to grow your plants - Out of Town Blog

  3. Pingback: How to Convert Plants to LECA: A Semi Hydroponic System • Maria Louise Design

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