Leca is an acronym for Lightweight Expanded Clay Aggregate. The word sounds complicated but it is simple to understand when explained.
Ideally, Leca balls are a growing medium, just like soil, which you can use to grow plants. Leca is an aggregate of baked clay balls that expand when they come into contact with water. Leca absorbs 30% of their own weight in water, making them an excellent substrate for plants that do not do well when over-watered.
In this article, you are going to find out more about Leca and why it is useful for growing plants.
Let’s dive in!
What is Leca?
As I have mentioned before, Leca is an acronym for Lightweight expanded clay aggregate. In simple terms, this implies that you have baked clay balls that soak up water and expand slightly.
The water that is soaked up in Leca can be used to water plants. Nonetheless, unlike soil, Leca is just a collection of clay balls and does not have any nutrients. As such, your plant will still need nutrients. You can add nutrients to the water.
Why Use Leca for Plants Instead of Soil?
Now that you have an idea about Leca, let’s have a look at some of the benefits that make it useful in plant growth.
1. Reduced Risk of Root Rot
Watering is made simpler when using Leca compared to when using soil. This is because you wll be watering when the water in the pot is finished.
Adding more water, even if the clay balls are still full of water will not cause the plant to be overwatered, since the plant absorbs moisture as it needs. If you were to add more water when using soil, you may end up soaking the soil and killing the plant due to overwatering.
Additionally, there is a reduced risk of root rot when you grow your plants in Leca. This is because Leca creates a lot of air gaps in between clay balls which aids in getting the needed oxygen to the roots of your plant.
2. Makes It Easy to Water Plants
The most important part of growing your plant in Leca is that its roots will not be in the water. When you grow your plants in Leca, you can develop a false bottom and raise the roots of your plants from the bottom of the pot. You can then add water until it is just under the roots of the plants.
Your Leca will start to soak up the water in the pot while keeping the roots away from the water. Your plants will then sip water that has been soaked into the clay balls.
Plants planted in Leca have an advantage over those that are planted in soil – they absorb moisture at a rate that is ideal for their health.
3. Reduces Risk of Pest Infestation
Since there is a reduced risk of root rot when you use Leca to grow your plants, bugs that are normally attracted by rotting roots won’t be drawn to your plants.
Additionally, Leca, unlike soil, is not a ‘live’ growing medium. Soil is termed as ‘alive’ because it has organic matter and nutrients, aspects that are missing in Leca. As such, pests that feed on organic matter that is present in the soil will not be attracted to your plant when you grow it in Leca.
4. You Can Easily Inspect Your Plant
The only time you can check the root system of your plants if you are growing them in the soil is during repotting. In between planting and repotting, you will not really know how the roots are doing.
Nonetheless, when you use Leca to grow your plants, you will be able to check the roots every single day if you decide to do so. This can afford you the opportunity to spot the early stages of root rot and intervene at a good time to save your plants.
How to Fertilize Leca
As mentioned before, Leca does not have any organic matter or nutrients. As such, you need to fertilize it so that your plants can receive the nutrients they need for growth. But how do you go about it?
Well, you can use most general hydroponic fertilizers. However, there are specific types of fertilizer you can use to fertilize your plants. These can range from growth hormones to nutrient fertilizers to boost root growth.
A Little on Hydroponic Nutrients
Hydroponic fertilizer has special ingredients that your normal plant fertilizer does not have. Normal plant fertilizers do not need these ingredients, since the soil supplies your plant with these nutrients.
Since Leca does not have any nutrients, the hydroponic fertilizer comes in handy to supply the nutrients that your plants will need.
Pros and Cons of Leca
The following table summarizes the pros and cons of Leca balls:
| Pros | Cons |
| Easier plant care | The higher initial cost to get started |
| Reduced risk of pests | More restricted pot choices |
| Reusable growing medium | More work to get started |
| Less week-to-week maintenance | You need special fertilizer |
How to Treat Leca Balls Before Using Them
Treating your Leca balls before using them is a good idea, so your plants can begin their semi-hydroponics life with a healthy start.
If your LECA balls are not soaked properly, they can cause your plants to grow a lot slower than they should.
A well-soaked LECA requires a lot less flushing than a not-soaked LECA. Here is how you can go about soaking your LECA balls:
Step 1: Rinse the LECA Balls
Unpack your LECA balls and give them a good rinse to get debris and clay dust off.
You can use a mesh laundry bag and a garden hose to do this outside. Avoid getting clay dust down your drain, it is not good for your pipes.
Step 2: First Soak
Soak your LECA for 24 hours in tap/ hose water. This first soak will eliminate the first wave of the crud out of the LECA.
Alternatively, you can allow the first soak to go on for two extra days and use your LECA without proceeding to step 3.
The simplest way to go about this step is by taking your laundry bag full of LECA and soaking it in a large plastic container. You can fit 50L of LECA in two mesh laundry bags.
Step 3: Second Soak
Proceed to dump out the soaking water and replace it with fresh hose/tap water. Soak for an additional 24 hours.
You can use your LECA balls after this soak. However, for high-value plants that you are keen to ensure get a good start, proceed with step 4.
Step 4: Dry and Store
If you are not going to use your LECA balls right away, you can dry and store them. You can dry them in mesh laundry bags – they allow amazing airflow. If you plan to use your LECA balls right away, you can skip this step.
NB: You can consider doing steps 1 to 4 in the summer outside for all the LECA balls you plan to use in the winter. Additionally, if you leave your LECA outside and they get rained on, that’s a double win since the rain will rinse them on your behalf.
Step 5: Third Soak
If you intend to use your LECA balls to grow high-value plants, an additional soaking wouldn’t be a bad idea. Consider using filtered/reverse-osmosis/distilled water for this step.
Some people prefer soaking LECA balls for over 14 days before use. Also, this is a good idea if you are using clean, dried LECA from previous steps.
Also, you can add CalMag (Calcium Magnesium supplement) to the soaking water, as well as any rooting hormones like KLN.
You can add these supplements as early as the first soak since Ca and Mg ions substitute for the less desirable soluble minerals in the LECA balls.
