Mulch

Mulch is a layer of material applied to the soil surface around plants to improve growing conditions. It helps conserve soil moisture by reducing evaporation, moderates soil temperature, suppresses weed growth, and protects the soil from erosion and compaction. Organic mulches also decompose over time, adding organic matter and nutrients to the soil, while inorganic mulches primarily provide a long-lasting ground cover without contributing nutrients.

Mulch types can be grouped as organic or inorganic. Organic mulches include bark chips, wood chips, shredded leaves, straw, hay, grass clippings, compost, and pine needles. These materials enrich the soil as they break down but may require replacement more often. Inorganic mulches include stones, gravel, plastic sheeting, landscape fabric, and rubber. These can control weeds and retain heat, but do not provide nutrients and may need more frequent replenishment or replacement.

Application guidelines emphasize a thin to moderate depth. A layer of 2-4 inches is common, adjusted for climate and mulch type. Keep mulch several inches away from the bases of trunks and stems to prevent rot and pest issues; avoid creating a “volcano” around the plant. Replenish organic mulches as they decompose, typically every one to three years, and inspect for compaction or drainage problems. For pathways or decorative areas, lighter depths or inorganic materials may be appropriate.

Environmental and maintenance considerations include the potential for pests or mold in damp conditions, and the possibility of nitrogen immobilization during the early stages of decomposition of organic mulches. Some mulches, such as cocoa hulls, can be toxic to pets. Selecting locally sourced, appropriately processed materials and applying them correctly can maximize benefits while minimizing drawbacks.