LECA is an acronym for lightweight expanded clay aggregate. It is used as an inert, soil-less growing medium.
LECA is a good alternative to soil for several reasons:
- Less prone to pests
- Helps promote aeration for root systems
- Can be sterilized and reused for a very long time, if not indefinitely
- Depending on environment, can require less watering than traditional potting soil
Preparing LECA
- Prior to using LECA, it is important to soak it for 24-72 hours. This allows the medium to absorb water so the clay balls don’t float.
- LECA is very dusty, so washing it thoroughly before use is essential.
- Some people sterilize their LECA - I only do this if it was recently used and I do not have time to dry it thoroughly and store it for awhile. I do not sterilize new LECA and have not had issues.
Planting in LECA
I prefer a net pot with an outer pot for my smaller, LECA-based plants. Typically filling the outer pot about 1/3 to 1/2 full is sufficient to wick water all the way to the top (more water for newer starts whose roots are not deep, let it naturally evaporate/use down to 1/3 - maintain 1/3).
Put a layer of LECA in the bottom of the net pot, then let your plant roots dangle as you fill in around it with LECA . For something with very shallow roots, fill in a majority of the pot and situate just the last bit of LECA around the roots.