As winter approaches, urban gardeners need to prepare their planter boxes for the cold months. Proper cleaning and storage will protect your containers from damage and ensure they're ready for spring planting. Begin by removing all plant material and soil from your boxes. Scrub the interiors and exteriors with a mild soap solution, using a stiff brush to remove any mineral deposits or stubborn dirt. For wooden planters, avoid harsh chemicals that could damage the material. Rinse thoroughly and allow them to dry completely in the sun if possible.
Once cleaned, consider applying a protective treatment appropriate for your planter material. Wooden boxes may benefit from a fresh coat of natural sealant, while metal containers might need a rust-inhibiting spray. Store your planter boxes in a dry, sheltered location such as a garage, shed, or covered balcony. If you must leave them outdoors, elevate them slightly to prevent water accumulation and cover with breathable fabric instead of plastic to prevent moisture buildup.
For those in extremely cold climates, adding an extra layer of insulation around stored planters can prevent cracking. If you plan to leave soil in your containers over winter, ensure it's completely dry first and consider covering the surface with mulch. Taking these steps will extend the life of your urban planters and make spring gardening much more enjoyable when warmer weather returns.