How much mulch do I need?

Mulch can instantly improve your homes curb appeal. But that's not mulch's only benefit. It also helps to improve the soil nutrients, regulate soil temperatures throughout the seasons, conserves moisture, and prevents weeds from sprouting. For new flower beds, you should add 3" of mulch. For established beds that already have mulch, you should be adding no more than 1" to 2" to the layer. Mulch over 4" deep can be harmful to your plants' health.