Book 29, Question 80
What is mulch, and why do gardeners love it?
Mulch is a layer of material spread over soil, usually two or three inches deep.
It holds moisture by slowing evaporation, blocks sunlight so fewer weeds sprout, and keeps soil cooler in summer and warmer in winter. As organic mulch breaks down, it feeds the soil and worms. Keep mulch a little away from stems to avoid rot.