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Sanseveiras on Leca

What is Leca and why is it useful for plants?

Leca is an acronym and it stands for: Lightweight expanded clay aggregate. It sounds very complicated, but it's quite easy to explain. Essentially, Leca is a growing medium, like soil, in which you can grow your plants. Leca is a collection of baked clay balls that expand when you soak them in water.

When you use soil, it's very easy to feed your plants, because the soil contains nutrients. Leca on the other hand doesn't contain any nutrients. So you might be wondering: why would you even consider using this for growing your plants? That's what you'll find out in this post. After reading this post, you'll understand why it's useful, after which you might even want to give it a try yourself.

In this guide, we'll go over these topics:

  1. What exactly is Leca?
  2. Why is Leca useful for growing your plants?
  3. How do you fertilize your plants in Leca?

Let's get right into it! I love using Leca and I want to tell you all about it!

What exactly is Leca?

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Close up of an Alocasia Zebrina growing in Leca Close up of an Alocasia Zebrina growing in Leca

Like I mentioned in the beginning, Leca stands for Lightweight expanded clay aggregate. In plain English, this means that you have baked clay balls that soak up a little water and expand slightly. The water that's soaked up in the clay balls can be used to water plants. However, unlike soil, Leca is just a collection of clay balls and doesn't contain any nutrients. All they do is soak up a little water and expand. Your plant will still need nutrients, so you'll need to add these nutrients to the water.

This doesn't get you any closer to understanding why Leca is useful, so let's change that!

Why is Leca useful for growing your plants?

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Now that you know Leca is just a collection of expanding clay balls, you might be wondering how this has any benefit for your plants. So here is a list of the benefits:

  1. It's easier to water your plants
  2. Less risk of root rot
  3. The risks of getting pests are reduced
  4. You can easily "check in" on your plants

Let's go over each of these benefits!

1. It's easier to water your plants

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As I've mentioned in "How to avoid overwatering your plants" the most important part of growing your plants in Leca is that the roots are not allowed to sit in water. When you use Leca, you can create a false bottom and raise your plants' roots from the bottom of the pot. Then you can add your water until it's just under the roots of the plants. Your clay balls can start to soak up the water in the pot, while keeping the roots away from the water.

Your plant's roots aren't sitting in water, so they'll absorb the moisture from the clay balls. Since your plants aren't sitting in water all the time, like often the case with soil, they can sip on the water that has been soaked into the clay balls. If your plants are really thirsty, they will start to grow towards the water that's at the bottom of the pot and absorb moisture directly from there.

Putting your plants in charge

The difference for plants growing in Leca, compared to plants growing in soil, is that the plant absorbs the moisture at a pace that's ideal for its health. When you use Leca, you're putting the plant in charge of taking care for itself. After all, the plant knows what it wants and needs to stay alive. When you use soil, you decide what the plant wants and needs. This can be very tough at times, especially for beginners.

If your plant is growing in soil and doesn't like to be watered a lot, but the soil is very moist, you're exposing your plant to a lot of this moisture. Leca prevents this from happening.

2. Less risk of root rot

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Clean roots on an Alocasia Zebrina Clean roots on an Alocasia Zebrina in Leca

When you're using soil, you're watering when the soil feels dry or the plant looks a certain way. Watering is much simpler when you're using Leca because you're watering when the water in the pot is gone. The plant has absorbed it all or the clay balls have soaked it all up. Adding additional water, even if the clay balls are still full of water, won't cause the plant to be overwatered. Your plant won't be overwatered, because the plant absorbs the moisture as it needs it. If you were to add more water when soil is still soaked, you might kill the plant and over water it.

There is also less risk of root rot, because the Leca leave a lot of air gaps between the clay balls. This helps to get the needed oxygen to your plants' roots. A very common cause of root rot is a lack of oxygen at the roots of your plants. Leca solves this problem and worrying about root rot is a thing of the past.

3. The risks of getting pests are reduced

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Sansevieria in Leca

As mentioned in the previous paragraph, you water your plants in Leca where there is no more water in the bottom of the pot. The plant will choose when to drink and avoid being overwatered. Because it's very difficult to overwater plants in this case, the chances of getting root rot are very low.

This means that bugs won't be attracted to the rotting roots and soil. Fewer bugs mean fewer pests. Another reason why using Leca reduces pests is because unlike soil, Leca is not an "alive" growing medium. Soil is organic matter with nutrients and is "alive". This means that it could also contain nutrients for insects. Insects usually carry and cause diseases for your plants, so avoiding them altogether helps you to reduce the chances of dealing with a sick plant.

In fact, two of my Alocasias, the Zebrina, and Polly, were sick and their roots were rotting. This attracted insects and almost killed both of the plants. After switching them to Leca and cleaning them every single week, they've recovered and are now growing again like before. It's safe to say that those plants will never touch soil again.

4. You can easily "check-in" on your plants

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Spider plant in Leca

When you're growing your plants in soil, the only time you'll really see the roots is when you're in the process of repotting the plant. In between planting and repotting them, you won't really know what the roots look like and how they're doing.

However, when you're growing your plants in Leca, you'll be able to look at the roots every single day if you choose so. This is not something you should actually do, because some plants don't like change. I clean most of my plants, which grow in Leca, at least once every 6 months. During this process, I also make sure to clean, or at least rinse, the Leca. This gives me an opportunity to have a look at how the roots of the plants are doing. The picture at the top of this post is an example of this. I can look at the progress of the roots and adjust the placement of the plant in the pot accordingly.

The fact that you can "check-in" on your plant so easily is what helped me to save my Alocasias from certain death. I was able to cut off rotting roots as soon as I saw them and prevent further rotting by cleaning the plant well. This took a lot of effort, but my plants are rewarding me by growing again.

How do you fertilize your plants in Leca?

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I mentioned that Leca does not provide your plants with the nutrients they need to grow properly. Leca only takes care of watering your plants. As such, you'll need to add nutrients to water yourself. Most general hydroponics fertilizer is fine, but there are also specific types of fertilizer you can use to help your plants. These can range from growth hormones to fertilizer to help the roots grow faster and stronger. I personally have no experience with these and stick to a general hydroponics fertilizer myself. This has worked well so far, so it may be something you can consider using as well.

About hydroponics nutrients (fertilizer)

Hydroponics nutrients (or fertilizer) contain special ingredients that your normal plant fertilizer doesn't have. Normal plant fertilizers don't need these ingredients, because the soil provides your plant with these nutrients. Since Leca doesn't contain any nutrients, the hydroponics fertilizer needs to have these missing nutrients to keep your plant healthy. This is why you can't use normal fertilizer for your plants in Leca: it's missing key ingredients.

Conclusion

Leca stands for Lightweight expanded clay aggregate. Essentially, it means they're baked clay balls that expand when you soak them in water. They're great as a medium for plants to grow in because it makes watering your plants much easier, you reduce the risks of getting pests, and you can easily "check-in" on your plants. The most important thing you have to think about when growing your plants in Leca is to never let their roots sit in water and to add a hydroponics fertilizer of some sort to the water. This way your plants get the nutrients they need and drink when they're thirsty. Hopefully, the benefits that I've listed in this post make you want to give it a try. I can highly recommend using it!

Thank you for reading this post! I hope it helps you to keep your plants healthy and beautiful! If you're looking for more guides on specific plants, you can always request a plant guide or donate a plant in order to get a guide for the plant you have trouble with.

Tags: leca, water, pests, growing-medium

Posted on: Apr 13, 2020 Last updated on: Jun 5, 2022

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