For thriving urban gardens, the soil in your planter boxes is crucial. While a regular potting mix is a good start, a specialized blend is often better. Standard potting mixes provide drainage and aeration but may lack the long-term nutrients and moisture retention needed for confined spaces.
For vegetables and herbs, enhance a quality potting mix with 1/3 compost for nutrients and 1/3 coconut coir or peat moss for moisture control. This creates a loose, fertile, and well-draining "container soil." Avoid dense garden soil, which compacts in planters, suffocating roots.
The best soil for planter boxes is lightweight, nutrient-rich, and retains moisture without becoming waterlogged. Refresh the top few inches each season with compost to maintain vitality. Your plants will reward you with stronger growth and higher yields.