The most exciting thing about plant care is experimenting with different mediums to grow your plant family. We’ve been exploring different ways to grow plants in water—one of those ways is utilizing LECA.
The plant community uses the terms “leca” and/or “hydroton” to refer to all types of expanded clay. LECA, specifically, stands for Lightweight Expanded Clay Aggregate - a collection of baked clay pebbles that expand when you soak them in water. You can use LECA for propagation, or you can have your plants live in it!
In non-gardening lingo, leca are baked clay balls that soak up water and expand. The water that Is in the leca balls can be used to water plants! Unlike soil, leca does not have any nutrients, which means liquid fertilizer is a helpful addition to keep your plants healthy.
LECA has become the newest trend in plant growing mediums for several reasons. Here is a list of some of the benefits of using LECA:
Fun fact: LECA is the name of a specific brand of expanded clay, which has since gone out of business due to the company-owned clay mine becoming depleted. Some common brands of expanded clay are Hydroton, Hydrocorn, and Hydro Korrels.
LECA can vary depending on the brand based on size, size variation, smoothness, and porosity. Each of these qualities influences your plants’ growing characteristics, so it’s essential to understand the differences and how they may affect your plants. Let’s go through them one at a time.
The size of the individual clay balls directly affects how much room your plant has to grow its roots. Larger clay balls allow more room for root growth, allowing for better oxygen delivery but less structural support for the plant.
Size variation focuses on the range of sizes within a LECA mix. We find that a LECA mix between small and large pebbles creates an excellent medium for your plant because the growing medium ends up being a bit denser. This allows for good oxygen delivery while also offering good structural support.
Smoother LECA packs loose, so it gives the plant more room for root development and oxygen delivery. The downside is that smooth LECA, much like larger LECA, offers less structural support.
Rougher LECA, on the other hand, packs denser and provides enough space for roots to latch onto the rocks. This is good, but it comes at the cost of less oxygen delivery. In addition, if or when you decide to repot the plant, it might be more complex and disruptive when using rougher clay balls. For this reason, rougher LECA is more suitable for vegetables and plants you don’t plan on repotting. One thing to also consider is that rougher LECA is harder to clean, so you’ll need to make sure to clean them between every reuse.
Now, let’s talk about porosity—or how much water each of the balls can absorb. The more porous the LECA, the more absorbent they are and the better the water moisture. This is great for most non-agricultural styles of hydroponic growing.
Before potting your plants in LECA, it’s critical to flush the clay balls until the water runs clear. When you first use LECA, you’ll find that they are covered in a dry clay residue from the clay balls making contact with each other while being packaged. The dust can cause health problems for your plants, so it’s important to wash this off before use.
If you're feeling a little lazy, you can also just soak the LECA for 2+ days to make sure you get rid of all the crud out. For high-value plants, we recommend a second soak for another day or so. You would want to change the water and let the LECA dry in between soakings.
It does require some patience, but this step will save you time, money, and energy later on!
The size of your vase depends on how big you want your plant to grow. However, you don’t necessarily have to be married to a particular size, being that you can always transfer your plant into a bigger pot later on.
We have also noticed that the transparency of the pot can influence how your plant grows in LECA. There are pros and cons to both. For instance, clear vases are more susceptible to algae—making the LECA harder to clean and potentially disrupting the root system. Non-clear pots, on the other hand, help lessen the risk of algae, but you can’t accurately track water levels, so you’re left guessing as to when you should add more.
A good rule of thumb is to choose your pot based on where you plan to keep your plant in LECA. For example, if you plan to have your plant in more direct sunlight, an opaque vessel is probably best—otherwise, algae growth is likely. But, if your plant will be out of direct light where algae growth is less substantial, a transparent pot works great.
Now that you’ve prepared your LECA and your plant’s new living space, it’s time to pot your plant in LECA! Before we get started, we have found that this growing medium works best for plants with an established root system.
First, if you’re transferring your plant from soil, you’ll want to start by gently removing all the dirt from your plant. Since LECA stays so evenly moist constantly, any soil left on the plant will be wet all the time and can lead to root rot or fungus.
Next is putting the root system inside with LECA. This step is pretty self-explanatory because it’s just like potting with soil. Grab your pot and fill it up to about ½ - ¾ of the way with LECA and submerge it in water. Then, place your plant's roots in the pot and fill the rest up with LECA. Try to arrange the roots so that they don’t touch each other to ensure that it’s less likely to pass rot on to the other roots if one root starts to decline.
The last step is just to add water! We recommend adding your liquid nutrients to the water before filling up your pot to distribute nutrients evenly. Then, pour in the nutrient water until it has just reached the bottom of the root system to avoid the roots sitting in water while still creating a moist environment.
Consistent Water Supply
Leca is a hydroponics system does the hard work for you. You won't need to water plants as frequently, because the open spaces within the leca pebbles naturally draw water up to the plant.
Soil loses it's nutrients over time, and should either be discarded and replaced or replenished. Leca just needs to be cleaned between uses, and a couple of drops of liquid fertilizer tailored to your indoor plants goes a long way.
Leca balls allow for more aeration as the air pockets between the clay balls allow more oxygen to reach the plant's roots. This prevents a well-known gardening disaster: root rot.
Leca pebbles can be used for almost every kind of plant. Many gardeners know the proper plant mix is hard to create!
Simply put, soil can make a mess. Especially when you want to bring in more house plants, fertilizer and soil may not be fun to deal with. The most mess you can expect with LECA is the dust from the porous material. Indoor plants without the mess is any gardeners dream!
There are still some cons when gardening with these little clay pebbles. Although the benefits may outweigh the cons when thinking about soil vs. leca... is there an even better alternative out there? Hint: stay tuned - the answer is YES.
Leca can cost up to for times the amount of your usual potting mix, its not a cheap transition. However, you won't have to keep venturing to garden centers to replace soil, leca does last longer than traditional soil. When reusing leca, make sure to rince off any organic matter, replenish water and fertilizer and transfer plants.
Fertilizers or necessary nutrients are usually included in indoor potting soil. However, with leca, you'll need hydroponics fertilizer for your plants.
Throw out the notion that you need drainage holes for your plants. Leca balls need a container that is closed bottom. The water is absorbed by the pebbles!
What we DON’T want to do is have the plant’s roots sitting in water. So avoid filling the entire pot or vase with water. Instead, you should bring the water up to just below the bottom of the root system. This puts your plant in charge of how much water it's receiving, and it can sip on the water that’s been soaked in by the LECA.
You don’t have to worry too much about refilling the water since LECA allows for the plants to grab water when they need it. However, when you see that the LECA is drying up and the roots are growing closer to the bottom of the pot, you’ll want to refill the water.
Nutrients offer long-term growth support, especially for plants in LECA. The liquid solution of water and hydroponic nutrients essentially replaces the nutrients that the plant would get in soil. We usually add 1-2 drops to the water before pouring it into your pot and repeat this step every 1-2 months.
Finding the right nutrients is a topic of its own, but we'd recommend finding a nutrient solution intended for hydroponic growth. We have a great nutrient solution to support plant health in our shop that you can check out here.
You should clean your plant in LECA about once every 1-2 weeks. This is a great time to check the root system and adjust the plant’s placement in the pot as necessary. If you’re planning on reusing the LECA, make sure to clean (or at least rinse) the clay before repotting your plant. Also, you want to be careful when removing the roots from the LECA because the roots can get stuck to the clay and the inside of the pot.
Leca solves many problems that traditional soil can create:
Leca balls protect plant roots, and get rid of messy soil. But what if there was an even simpler solution for plant owners? If you want to growing plants - it just got easier. Hydroponic gardening allows for indoor gardeners to have more plants with even less hassle.
Modern Botanical plant frames and propagation stations allow green thumbs and black thumbs alike to bring more plants into their home. When growing plants with just water, the only thing you have to worry about is good lighting and replacing the water at least once per month.
This growing medium has so many fantastic benefits beyond being the new fad in plant care. Of course, LECA may work differently for everyone (what works for us may not work for you) based on different environments and care routines. Nonetheless, it’s a really fun medium to work with and to learn more interesting things about plants.
We would love to hear about your experiences with LECA! Follow us on Instagram @modernbotanicalshop for more growing tips and tricks!