Garden Q&A: I found little green and brown pellets in my garden. What are they?

Whether you're a gardening beginner or expert, Irish Examiner columnist Peter Dowdall has the answer to your questions  

Biochar fertiliser. Picture: iStock

Question

This year, while preparing my garden for setting, I found a lot of small brown and green balls or pellets. I cannot remember seeing them before and am wondering what they are.