Mulch & Gravel Calculator

A consistent 2–3 inch layer of mulch is one of the highest-return investments in landscaping. It suppresses weeds by blocking sunlight from reaching the soil, retains moisture — reducing watering frequency by 25–50% in summer — moderates soil temperature, and gradually adds organic matter as it breaks down. At a 2-inch depth for annual top-dressing, one cubic yard covers 162 square feet. At 3 inches (recommended for new beds), the same yard covers 108 square feet. For weed suppression in problem areas, 4 inches is effective, though it can reduce oxygen exchange for shallow-rooted perennials.

Mulch type matters for both appearance and long-term performance. Double-shredded hardwood bark is the most common and effective choice for ornamental beds — it interlocks and stays in place far better than single-shredded or chip mulch. Pine straw is popular in the Southeast for its light weight and natural look. Stone and gravel mulch is permanent and low-maintenance but raises soil temperature and isn't suitable for most flowering perennials. Fresh wood chips from a tree service are free or inexpensive but can temporarily rob nitrogen from the soil as they decompose — keep them away from the root zones of young plants and vegetable gardens.

Never pile mulch against tree trunks or plant stems. The classic 'mulch volcano' causes bark rot, fungal disease, and eventually kills the tree over several years — even though it looks tidy. Keep a 4–6 inch gap between any mulch and the base of trees and shrubs. For large areas over 3 cubic yards, buying bulk mulch delivered by the truckload is substantially cheaper than bagged product from a garden center — typically 50–70% less per cubic yard. Spread it the same day as delivery if possible; rain quickly compacts a large pile and makes it harder to distribute evenly.