Organic Garden Soil For a healthy organic vegetable garden, you need to start with healthy soil. The most important component in the soil is the organic matter, such as manure, peat moss, or compost—the latter is the best option because it contains decayed microorganisms of previous plant life. Those microorganisms supply plants with the nutrients they need. You can create your own compost pile by designating an area or bin where the organic matter will decompose. Or you can buy it in bulk if you have a large garden, or use bagged compost available at garden centers and home improvement stores. Reduce weeds by spreading a 1- to 2-inch-thick layer of mulch on the soil. It creates a barrier that prevents weeds from getting sunlight and from germinating. This mulch layer also prevents fungal disease spores from drifting onto plant leaves. Use an organic material (such as cocoa hulls, weed-free straw, or newspaper) as mulch so as it decomposes it adds beneficial organic matter to the soil.