I want to amend my soil with compost. What is the proper compost-to-soil ratio?
There’s no hard and fast rule. It’s hard to add too much organic matter to garden soil, and every bit helps maintain good soil structure, improves moisture management, and increases nutrient-holding capacity. Generally, gardeners are advised to add a 1- to 2-inch layer of compost each time they till, turn, or replant a bed or garden. It’s also helpful to add partially-decomposed organic matter, such as rotting leaves or old straw, and fresh green materials like grass clippings or a green manure crop. This provides a rich array of materials in various stages of decomposition and with different nutrient levels to boost and widen the soil microbe population, and ultimately, soil quality. Your climate (temperature and humidity), soil pH, and soil type also affect the rate at which organic matter is used up by microbes, so check with your County’s Cooperative Extension office for regional specifics.
