Vermiculite is used to increase water and nutrient retention as well as aeration. 

Helps to improve plant growth, prevent root rot; Vermiculite will never rot, deteriorate or mold. It is odorless, non toxic and sterile.

Ideally used with water-loving plants. You can mix vermiculite in your garden or potting soil to help improve water retention. It can also be used as a potting medium for seedling germination with a small amount of fertilizer.