Compost can be made up of almost everything you throw away in your kitchen: fruit scraps, vegetable waste, paper napkins, newspaper, even coffee grounds. But what is composting? It’s a magic trick by which you turn trash into nutrient-rich soil (and help save the Earth). If you want to start composting, or just learn more, Los Angeles County’s Smart Gardeningworkshops will teach you, for free, how to improve your lawn or garden while cutting waste. No reservation needed. Workshops are about 90 minutes, held at various learning centers, libraries, parks and schools around the county. After the workshop, you’ll receive some seeds and mulch for your garden just for attending, and you can purchase composting bins at a discount — $40 for regular composting bins and $65 for “worm” composting bins, which include one-half pound of worms. At some workshops, they raffle a free composting bin. —Eve Weston