Using regular garden soil in your urban planter boxes is generally a bad idea. While it might seem convenient, garden soil is designed for in-ground use and creates several problems in containers. It compacts easily, restricting oxygen and stunting root growth. It often lacks proper drainage, leading to waterlogged conditions and root rot. Garden soil can also harbor pests, diseases, and weed seeds you don't want in your confined planter space.
For thriving urban plants, use a high-quality potting mix specifically formulated for containers. These mixes are lighter, fluffier, and provide excellent aeration and drainage. They typically contain ingredients like peat moss, coconut coir, perlite, and vermiculite. Some mixes include slow-release fertilizers to nourish your plants. For deeper planter boxes or raised beds, a "garden soil" product designed for raised beds—which is a blended soil, not pure topsoil—can be a suitable and cost-effective option. The right soil is the foundation for healthy roots, which is the secret to a successful and productive urban garden.