As the growing season ends, preparing your urban planter boxes for winter is crucial for their durability. Start by removing all spent plants and soil to prevent disease and pests from overwintering. Thoroughly clean the interior and exterior of the boxes with a mild soap and water solution; for wooden planters, this is especially important to remove salt and mineral buildup. Allow them to dry completely.
For wooden planters, applying a fresh coat of sealant or linseed oil can protect against moisture and freeze-thaw cycles that cause cracking. If possible, move lighter containers to a sheltered location like a garage or shed to shield them from harsh elements. For permanent or heavy boxes, consider insulating the roots of any hardy perennials with mulch and covering the box itself with a breathable fabric or tarp to prevent ice damage.
Elevating planters slightly off the ground with bricks or "pot feet" ensures proper drainage and prevents the bottom from sitting in water, which can lead to rot. Avoid storing soil in them over winter if they are empty, as it can become compacted and soggy. By taking these proactive steps each fall, you effectively winterize your planters, ensuring they remain structurally sound and ready to thrive for many springs to come.