A mulch ring is a circular border surrounding the base of a tree. Recommendations for proper tree planting include a mulch ring that covers the soil beneath the tree canopy.
One benefit of using a mulch ring around trees in a lawn area is to prevent maintenance equipment from coming too close and damaging the trunk. Plants grown directly
beneath the tree canopy compete for water and nutrients. A mulch ring keeps the soil covered without creating competition.
Use organic mulch, if possible, for the same reasons it is selected for planter beds in
general. The mulch ring around trees in a lawn should be at least three to six feet in
diameter depending on the overall size of the tree. Ideally the mulch ring should extend
to the drip line of the tree. This means the ground beneath the entire canopy of the tree
should be covered protecting the majority of the plant roots.
Create a flat, donut-shaped ring of mulch around the tree leaving a 4–6-inch diameter circle of bare soil at the center so mulch isn’t right up next to the trunk to prevent rotting. The mulch should be 2-4 inches deep and reapplied annually. If applied too deep (more than four-inches) the mulch can actually restrict oxygen from the soil and negatively affect root development.
