LECA, also known as lightweight expanded clay aggregate, is a collection of kiln-fired clay baked into round balls. Used in all types of gardening functions, these porous pebbles allow for superior drainage and air circulation so roots get plenty of oxygen. They are pH neutral, non-flammable, odorless, and do not decay or shrink. Use alone or with other materials such as peat moss, compost, or potting soil. It aids in retaining moisture and provides aeration needed for plant growth. Mix with your favorite soil medium: Improve the drainage of your soil mix by adding LECA. Mix with your soil choice, organic compost, natural soils or composed bank, to help anchor the roots of young plants so they grow stronger.