Composted leaf mulch is incredibly good for your lawn, flower beds, veggie beds, etc. Is it so Ph neutral (very, very slightly acidic) that it doesn't even injure seedlings. You can grow seeds in a mix of leaf compost and potting soil. It loosens up compacted soil improving soil structure and drainage. I've never put any chemicals in my lawn, always mulch-mow my leaves, and my gardens are fantastic.