1. Plant-based: Straw, pine needles, cottonseed hulls, tree bark, shredded tree leaves
Best for: All gardens
Don’t forget: Sprinkle a nitrogen source, such as agricultural cornmeal, on the surface before mulching so that the mulch doesn’t rob the soil of the nutrient as it breaks down.
2. Mineral-based: Coarse sand, greensand, ground granite, lava rock, oyster shells
Best for: Mediterranean natives such as rosemary, sage, thyme and winter savory
Don’t forget: Add more of this type of mulch after a heavy rain and during the winter.