Vermiculite

Description

Besides water retention, vermiculite’s other benefits for gardeners include:

Causes plants to germinate and grow more quickly;
Helps anchor roots;
Prevents root rot;
Aerates soil by loosening it, so roots can grow more easily;
Lightweight;
Nontoxic;
Odorless;
Sterile, which prevents fungal growth;
Helps nutrient retention by naturally reacting with soil compounds to make other nutrients available, including calcium, potassium and magnesium;
Has a neutral pH (although it will raise soil pH slightly because of some compounds found within it);
Permanently improves soil drainage.