Mulch moderates soil temperature, holds moisture and suppresses weeds.
- Wood chips: never dig them in — they steal nitrogen; keep on top. Put old newspaper beneath in weedy areas.
- Straw: easy to spread, though some weeds poke through.
- Dry grass/hay: may carry weed seed or herbicide residue — know the source.
- Dry leaves: free and handy; rot slowly.
Cool-season greens want mulch to stay cool; heat-lovers get mulch once the soil has warmed.