Question: What is the difference between outdoor soil and potting soil?

Answer: Some potting soils are formulated specifically to meet the needs of certain plants. For example, potting soils for cacti have excellent drainage; those for acid-loving plants have a low pH; those for starting seeds are sterile to minimize disease problems. Some potting soils also contain slow-release fertilizers. In contrast, outdoor soils vary widely in texture, drainage properties, and nutrient analysis; they may also contain insects or diseases that could affect your plants. Although in some cases regular garden soil will be adequate for container-growing, in general you will get better results using a potting soil that is formulated for excellent drainage and other beneficial characteristics. For large containers, a mix of garden loam, compost, and potting soil may be adequate.