Don't bag up your fallen leaves and send them to the landfill. Dump them into a wire bin instead and let them decompose. This DIY bin is 3' tall and 4' in diameter. According to author Michelle Balz, it can hold about as many leaves as you'd stuff into nine paper bags. Once the leaves settle, you'll have more room to add more. The resulting compost is called leaf mold, and while it's not as nutrient-rich as traditional compost, it's still a valuable amendment for improving your soil and helping retain moisture.