What is Leca and How to Use It
Written by Natalie Anstey
LECA is a relatively new planting medium that has become really popular with hydroponic gardens.
Hydroponics sound daunting but are actually pretty simple. Hydroponics are when you grow plants using anything other than soil..so that could be water, pebbles, sand…any medium that doesn’t have any nutrients. Making LECA is the poster boy for hydroponics!
What is Leca?
LECA stands for Lightweight Expanded Clay Aggregate but in layman’s terms LECA are balls of natural clay that have been baked at high temperatures to form a planting medium that look like mini coconuts. They are inorganic, meaning they have no nutrients like soil does, so a specialist hydroponic fertilizer should be used.
Benefits of Using Leca
There are many benefits to using Leca, such as:
1. LECA is inorganic so whilst it doesn’t naturally hold any nutrients, it doesn’t hold any pests or diseases either. No more bugs lurking in the soil!
2. The risk of overwatering is reduced significantly. When planting with LECA the bottom third of the pot should be free from roots. When watering, only water with enough water to cover this bottom third. This means that the roots can naturally take up what they need rather than be overwatered.
3. Its lightweight nature allows air to flow freely through the roots, meaning healthier roots and root rot will be a thing of the past!
4. You can check how your plant is doing more easily! Although it is not recommended to move your plant too often, you can lift it up every once in a while to see how the roots are developing and whether the LECA might need a refresh.
5. They have a neutral pH which means they can be used with any plant.
6. They don’t rot and are reusable! Simply give the LECA a clean and you can use it again in another plant!
How to Use Leca With Your Plants
LECA is used as a planting medium instead of soil. They are naturally porous so they soak up water and allow the plant to drink more autonomously, taking only what it needs.
When you get your LECA, the first thing you should do is soak it in water for at least 12 hours to let it take up all that moisture to water your plant. Once you have done this, fill the bottom third of your pot with LECA and you can now think about adding your plant.
When you're ready to pot your plant in the Leca, take your plant and remove all the soil. You do not want soil to become mixed with the LECA. You can either take cuttings or gently remove all the soil from the plant. Then plant as normal backfilling your plant with LECA.
Rule of (Green) Thumb: LECA can also be used in a decorative way. If you sprinkle them over the top of your soil, it can be used to keep pests away and keep moisture in! They can also be used as drainage in the bottom of pots as air (and water) can flow through.
How to Water Leca
One of the biggest benefits of LECA is that the roots do not sit in water which eliminates any kind of root rot (YAY!) When watering, add enough water to fill the bottom third of your plant or just below the roots - just don’t let the roots be sitting in water.
It is also important that the bottom of the pot has no drainage holes, otherwise the plant will not be able to suck up the water from the reservoir of excess at the bottom.
Rule of (Green) Thumb: LECA must always be used with a hydroponic fertilizer as it contains no nutrients.
What to Plant in Leca
About almost anything! There are plants that will naturally take better to LECA than others. As a general rule, the more robust plants or plants that like to dry out in between watering can be planted in LECA, along with plants that have fast growing roots or like a less fertile soil.
- Spider Plants
Things to Be Mindful of When Using Leca
Although LECA is a fantastic medium to grow houseplants, there are some things to be mindful of:
1. LECA has a larger cost outlay than soil to begin with. LECA can be up to 5 times the price of “traditional” soil but it won’t lose any nutrients or have to be replaced because it doesn’t have any to start with! LECA is also reusable, so if you want to freshen it up or use it for another plant, just give it a rinse under the faucet and you can reuse!
2. LECA has to be used with hydroponic fertilizers. You can’t just use normal fertilizers as these do not have enough nutrients to compensate for the soil - so a specialist fertilizer must always be used.
3. It may sound like common sense - but DO NOT USE LECA IN POTS WITH DRAINAGE HOLES. The water will drain out and cannot be used by the plant roots.
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