Potting soil is available for purchase at local garden centers, at home-improvement stores such as Lowe's, and in the garden departments of major chain stores such as Target. Most retailers that carry potting soil offer multiple varieties.
Potting soil is intended for use in both indoor and outdoor containers as well as window boxes. Some soils are designed specifically for seed starting, while others are appropriate for general container gardening and repotting.
High-quality potting soil helps ensure healthy plant growth, while cheaper soil mixtures include ingredients such as sand, sedge peat and muck, which inhibit drainage. A high-quality soil contains ingredients such as peat moss, aged bark, lime and perlite. These ingredients create a loose soil that lets plant roots spread out easily, and water drains through this type of soil quickly.
Potting mixes that contain time-released fertilizer help support growth for a few months after the initial planting. Fertilizer is also available in liquid and granule form and can be added to the soil at regular intervals throughout the growing season. Organic potting soil helps fruit and vegetable growers maintain a chemical-free growing environment. Compost, peat humus, vermiculite and other additives are available to let gardeners customize each container environment for a particular plant or group of plants.