mulching around perennials and trees
How much mulch do you need to put around your plants? Since the idea is to create a blanket, use the soil as a gauge — if you can see soil, you need more mulch. For most plants, a layer of 2 to 4 in. is deep enough.
MULCHING AROUND PERENNIALS — Spread mulch completely around a plant so all the roots can benefit. Just be sure to keep it at least an inch away from the stem and leaves. Mulch placed too closely to a plant will limit air circulation and create an environment where insects and diseases can flourish.
For plants that have a low-growing or mounding habit, like the coral bells you see above right, you can mulch around the outermost leaves. These act as a self-mulch, keeping the soil cool under the plant and helping to conserve moisture.
MULCHING AROUND TREES — Mulch helps trees most if it extends to the dripline. You can find the dripline by drawing an imaginary line from the outermost leaves on the tree to the ground. That’s a gauge of how far the roots extend on the plant. Be sure to keep mulch at least an inch away from the trunk, as well. Newly planted trees benefit the most from mulch because their roots haven’t grown enough to get water and nutrients from deep in the soil.