As the growing season winds down, cleaning your urban planter boxes is a crucial task for preventing disease and ensuring success next year. Start by removing all dead plants and roots. Shake off excess soil from the roots and dispose of diseased plant material in the trash, not the compost. Next, empty all the old potting mix onto a tarp. While some mix can be reused if plants were healthy, it's often best to start fresh to avoid pathogen carryover.
Now, scrub the empty planter boxes thoroughly. Use a stiff brush, warm water, and a natural cleaner like diluted white vinegar or a mild dish soap. For boxes that housed diseased plants, disinfect them with a solution of one part bleach to nine parts water. Rinse the planters completely and let them dry in the sun, which has natural sanitizing properties.
Don't forget your tools! Clean and disinfect trowels, pruners, and other equipment used in the containers. Once everything is dry, store your planters in a sheltered location like a garage or shed to protect them from winter cracking. This simple end-of-season ritual removes overwintering sites for pests and fungal spores, setting the stage for vibrant, healthy plants when spring returns.