LECA is lightweight expanded clay (Lightweight Expanded Clay Aggregate) crated by heating marine clay to temperatures of 1150 degrees centigrade. Hence, these particles are essentially burnt clay with thousands of air-filled cavities. LECA is a natural products. It has sues in the construction industry as an aggregate, insulation in flooring and roofing and for drainage.
It is an ideal horticultural aggregate, since it has excellent ventilating properties. The cavities within the particles help retain water and prevent evaporation from the soil. It is chemically neutral, cleaner than soil and has no pests or fungi. As a hydroponic medium, it’s weight also allows it to be used in a variety of growing beds from PVC guttering to individual pots.
Common uses of in horticulture:
Hydroponics is probably the most intensive application for Leca in South Africa.
Leca is the ideal medium to use when building green roofs and sports pitches as it creates a very light drainage medium. This can also be the case for urban landscaping.