How to Spread Mulch

Prepare the garden soil surface as soon as the soil has warmed up by removing all weeds and surface debris, such as sticks and fallen leaves. Ohio State University warns that mulching too early while the ground is still wet and cold can create poor oxygen levels in the soil, which can inhibit proper plant root growth. Generally, start preparing to mulch in the late spring.

Spread mulch for trees and shrubs. Pour your favorite mulching material on the soil's surface to a thickness of 4 inches. Rake out the mulch 6 feet in all directions from the tree or shrub, and then pull back the mulch at the tree or shrub's base to keep a 1- to 2-inch mulch-free zone all around the plant. Allowing the mulch to touch your tree or shrub can cause decaying of the plant's bark.

Apply mulch for your flower beds or garden beds. Pour enough mulch to cover the entire bedding area to a depth of 3 inches, and then use your hands to brush back the mulch around each of your plants to keep it from touching their stems.

Replenish your mulch as needed throughout the year to maintain a 4-inch thickness for your trees and shrubs, and a 3-inch thickness for your flower or garden beds. This is sufficient for blocking out weeds and conserving soil moisture, but don't let it build up beyond 4 inches. This can form too impenetrable a layer that can deny your soil both oxygen and water.