Leca: A How-To Guide to Lightweight Expanded Clay Aggregate

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If you want an easier, bug-free way to grow your plants, you may want to consider using LECA. LECA, also known as Lightweight Expanded Clay Aggregate, is a growing medium that is quite popular all around the world.

Houseplant enthusiasts use LECA for its convenience of use while providing adequate water and oxygen.

LECA consists of baked clay balls that grow in size when soaked in water and gradually release the retained water onto your plants’ roots.

This is the most popular method in hydroponic gardening, where plants are grown completely without soil. Using LECA, you can make sure your plants are getting just the right amount of water and oxygen to thrive.

If you haven’t had your hands on LECA yet, give it a try and see how it can benefit your plants. This affordable, eco-friendly and reusable growing medium might just be your favorite method for growing plants.

Benefits of using LECA

Lightweight and Eco-Friendly

LECA is an environmentally-friendly growing medium made from heating clay to extreme temperatures. These high temperatures cause the clay to expand into lightweight, porous balls. You can use this growing medium again and again.

Reusable and Sterile

LECA is reusable, so you can use the same porous balls for multiple plants. I love using LECA for many of my plants because it reduces the odds of pests becoming an issue and I can see the healthy root growth through the LECA balls.

LECA is also sterile which keeps unwanted pathogens away, making this a safe and clean choice for both indoor and outdoor plants.

Healthy Drainage and Oxygen Flow

Since LECA is pourous, this allows it to supply healthy oxygen flow around your plants roots while allowing proper drainage. So if you’re someone who tends to overwater your plants, you should definitely consider using LECA for healthy plant growth.

Using LECA ensures you have a balanced moisture level, so you never have to worry about root rot or not watering your plants enough.

Pest and Fungus Resistance

If you’re someone who has trouble with annoying pests and fungus, LECA greatly reduces the risk for both of those issues.

Since LECA is sterile and has non-organic properties, pests do not find it appealing which means they won’t inhabit the plants. This means no infestations and instead, you’ll get healthier and faster growth on your plants.

As if this wasn’t enough, LECA also provides an effective drainage system that drastically lowers the chance of fungus growth, so you never have to worry about that.

Here’s a quick recap of why you should use LECA:

  • Eco-friendly
  • Lightweight and easy to handle
  • Sterile and reusable
  • Increased oxygen levels
  • Allows proper drainage at all times
  • Greatly reduces risk of pests and fungus

Using LECA for your houseplants makes plant growing easier. The health and well-being of your houseplants is greatly enhanced.

Using Leca for Plant Care

Water and Nutrients

LECA, also known as Lightweight Expanded Clay Aggregate, makes it almost effortless to know when to water your plants and give it nutrients. This is because you can always see the water reservoir line when using LECA.

Before using LECA, make sure to soak the balls in water and while you’re waiting on that, prepare a nutrient solution that you can then add to the water reservoir.

Using LECA allows you to consistently supply water to you rplants, providing them with the best care possible since you’re never underwatering or overwatering the plant.

This means you don’t have to worry about water frequency anymore. Instead, all you need to do is monitor the water level of the plant and top it off with water as needed.

A plant growing in LECA still needs nutrients to thrive, so you’ll want to consider using a liquid fertilizer like Flora Gro or Earth Medicine’s LECA fertilizer.

I have tried Earth Medicine’s LECA fertilizer and recommend it for houseplants. Simply follow the directions on the package of whichever fertilizer you choose and then add it to the water reservoir.

Preventing Root Rot

If you tend to overwater your plants, LECA is made just for you. LECA prevents root rot and overwatering because it elevates the roots, providing the roots with water and oxygen, which are equally important in plant growth.

By providing the right amount of water all the time, you’re setting your plants up for success.

Avoiding Pests and Bugs

One of my top reasons for using LECA is for its reduced pest and bug risk. Houseplant soil is a great breeding ground for pests and bugs, especially if you give your plant too much water (or not enough).

LECA is made or porous balls that have no soil whatsoever, making it a much easier plant experience since you’re likely to never encounter bugs with this growing medium.

Before putting houseplants into LECA, make sure to wash it thoroughly since it’s quite dusty when it’s fresh out of a bag. This also helps make sure your plants will have a clean and healthy environment from the start.

Preparing Leca for Use


Before you use LECA, make sure to properly rinse it to remove debris or dust. Grab a bucket and fill it with water. Make sure to rub and clean off the dust in the bucket of water as best as you can.

Some people say to repeat this process until the water runs clear. However, I don’t find that necessary. I simply rinse it once and then use it.

I’ve read from many people to never wash LECA in your sink because of the dust that comes off. It may be able to settle into your pipes and you don’t want that to happen. Stay on the safe side and rinse outside under a hose or in a bucket or water (and then dump the bucket of water outside).


Now that your LECA is rinsed and cleaned, it’s time to soak the LECA in water.

This step is crucial because it ensures the LECA is going to hold moisture effectively for any houseplants. Fill a container with leca and water and let it soak for about a day. Use tap water or filtered water for this step, it’s completely up to you.

During this 24 hours of soaking, the LECA will absorb the water and expand in size.


Now that the LECA is soaked, it’s time to size the LECA for your plants growing containers. It’s crucial to provide an adequate buffer at the bottom of the container so your plants roots are not sitting in water.

This buffer ensures the LECA will absorb water and distribute it to the roots without having the roots sit in water 24/7.


If you plan to reuse LECA but aren’t immediately using it for plants, proper storage is important.

Once your LECA is rinsed and dried, store it into a breathable container like a mesh bag or plastic contianer with holes in it for air circulation. This prevents mold and mildew from growing on the LECA.

Growing Plants in LECA

Now we will focus on all of the different plants that you can grow in LECA, focusing mainly on indoor houseplants, vegetables and orchids, as well as how to propagate plants in LECA.


Using LECA as a growing medium for your houseplants has tons of benefits, including improved drainage and oxygen flow. Plus, you never have to worry about bugs or overwatering.

To start using LECA for houseplants, rinse and pre-soak the LECA for 24 hours. Then, fill the container 1/3 of the way with water/nutrients. Filling the container 1/3 allows the LECA to wick up what it needs and provide water and nutrients to the roots for healthy growth.

Here are some houseplants I have in LECA.

You can use LECA for a variety of plants, including:

  • Philodendrons
  • Scindapsus
  • Monsteras
  • Hoyas

Vegetables and Orchids

You can use LECA for other plants including vegetables and orchids. The process is similar: rinse and soak LECA, place plants in LECA, and top off the reservoir whenever it gets low.

For vegetables, put 2-3 inches of LECA at the bottom of the container. Use a liquid fertilizer that matches the vegetables nutrient requirements since LECA doesn’t have any nutrients.

For orchids, make sure the orchids roots are barely touching the water reservoir, and let the LECA do the work for you by pushing the water up toward the roots.

Plant Propagation

LECA can be used for plant propagation, but I honestly find it to be an extra step you don’t need to take. I like to propagate my plants in plain water next to a windowsill.

If you’d still like to propagate with LECA, rinse and soak the LECA and place your plant cuttings into the pot. Make sure to keep 1/3 of the pot with nothing besides LECA and water, and use the rest of the pot for your plants roots.

Plants thrive in LECA, so get ready to play with it and explore this new growing medium.

Leca vs Common Growing Mediums

LECA is quickly becoming a popular growing medium, but it’s still not quite as used as traditional growing mediums like potting soil, compost, peat moss, and coconut coir.

Now, we will go over LECA vs the most common type of growing mediums.

Potting Soil and Compost

Many gardeners typically use potting soil and compost as their go-to method for growing plants. These two growing mediums provide essential nutrients and help maintain moisture for the plants roots.

LECA is quite different since it’s made from porous clay balls. However, it has a dramatically reduced risk of pests which means easier plant care and maintenance.

Unlike LECA, potting soil and compost need to be replaced periodically. Whereas LECA can be reused many times, making it a more eco-friendly and cost effective option.

Peat Moss and Coconut Coir

Peat moss and coconut coir are popular options for the more advanced houseplant grower.

This is because these growing mediums are known for their water retention and aeration abilities. This allows for excellent plant growth, however they come with environmental concerns.

Peat moss is a natural material sourced from peat bogs. These are taken from fragile ecosystems that take centuries to form. Removing peat moss also contributes to the release of carbon dioxide.

Coconut coir is a more sustainable choice compared to peat moss, but it still requires transportation from tropical regions, increasing its carbon footprint.

LECA offers many advantages because of its ability to keep pests away, easy maintenance, affordability, and environmentally friendly.

Hydroponic Systems with LECA

In this section, we focus on choosing fertilizer for your hydroponic system with LECA.

Hydroponic Nutrient Solutions

Since LECA doesn’t come with nutrients, you need to use proper nutrient solutions to grow healthy and strong plants. Fertilizers come with essential macro and micro elements that plants need in order to survive.

Best tips for managing fertilizer in hydroponic systems using LECA:

  • Change the fertilizer solution every 2 weeks to ensure plants are receiving fresh nutrients.
  • Monitor the pH level of the fertilizer solution regularly. Maintain a pH value between 5.5 and 6.5. This helps ensure there is healthy nutrient absorption.
  • Follow directions closely when using fertilizer in hydroponics. If you use too much fertilizer or not enough, it can lead to nutrient deficiencies or toxicities.

Choosing the Right Hydroponic Fertilizer

You need a particular type of fertilizer for LECA hydroponic use.

When it’s time to select a fertilizer, think about the following things:

  • Pick a fertilizer designed for hydroponic plants. These fertilizers are made to dissolve easily into water.
  • Choose a fertilizer that provides marco and micronutrients.
  • What does your plant need nutritionally? Some plants may require more nitrogen, while others may need more phosphorus or potassium.

By choosing the best nutrient solution for hydroponics, you’re making sure your plants will thrive in the LECA setting.

Maintenance and Troubleshooting

Fertilizing and Flushing

To ensure your plant has healthy growth, fertilize them consistently and regularly. It’s important to note that LECA doesn’t contain any nutrients whatsoever, so you need to provide them with a fertilizer.

Follow the directions on the fertilizer instructions section. To stay on the safe side, I always dilute recipes in half and test things from there. I find that many recipes are made way too strong for my little baby houseplants.

Optionally, you should flush your LECA every month or so to eliminate salts and deposits from forming through the water and LECA. Your flushing schedule depends on what type of water you have.

To flush, all you do is remove the plant, rinse the LECA thoroughly, and put the plant back into the container with new water.

Repotting and Root Trimming

Plants grow quickly in LECA, which means their roots expand and can become overcrowded in LECA. Repotting your plants is necessary in order to maintain healthy plant growth.

When it’s time to repot a plant, gently remove the plant from the LECA container and inspect the roots. Make sure there is no damage on the roots and trim if necessary.

Common Issues and Solutions

  • Algae: LECA is prone to algae growth. To prevent this from happening, use opaque pots that block sunlight. Make sure to change the water regularly.
  • Transitioning to water roots: When transferring a plant from soil to LECA, soil roots need to transition into water roots. Closely monitor your plant for the first month after transferring the plant. You can avoid any issues with this transition by providing a higher water level in the beginning. This helps the roots adapt to their new water environment. Slowly decrease the water level over time.
  • Root rot: You may find leaves that are wilting or turning yellow or brown. This might be a sign of root rot. Remove the plant and inspect the roots. If the roots feel soft and mushy, this is root rot. Trim any rotten roots and make sure the water level isn’t too high or drowning the roots.

If you’re new to LECA, it’s going to take some adjustments and practice. It’s well worth the time it takes to learn about LECA because of it’s cost effectiveness, reduced risk or pest issues, and it’s low maintenance.

Common questions

Can you use LECA for any plant?

I wouldn’t use LECA on cactai since they rarely need water, but I have used LECA for succulents like echeverias. I typically don’t do great with succulents but LECA makes it incredibly easy to care for these plants.

Can you mix LECA with soil?

I have mixed LECA with soil only to increase my potting mixes drainage rate. I’ve been experimenting with this and find it helps with improved oxygen flow around the plants roots.

Do I need to boil my leca?

There’s a lot of speculation out there on whether or not you need to boil LECA before using it. I have never boiled LECA and find it’s just an added step that isn’t necessary to have success with LECA.

If you’re not using LECA yet, it’s time to jump on the bandwagon and see all the benefits LECA has to offer.

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