These little balls are a type of mineral product called perlite. Every ingredient in those mixes have a beneficial effect on plants, and perlite is no exception.
https://www.trees.com/gardening-and-landscaping/perlite?msclkid=9b2c4a88b4e411ecac3252f1364ca82a
Perlite Contains…
- 70-75% silicon dioxide
- Aluminum oxide
- Sodium oxide
- Potassium oxide
- Iron oxide
- Magnesium oxide
- Calcium oxide
- 3-5% Water
Mws R Writings 