Refreshing the soil in your urban planter boxes each growing season is essential for maintaining healthy, productive plants. Begin by removing the top few inches of old soil and any plant debris from the previous season. Gently loosen the remaining soil with a hand fork to improve aeration without disturbing established plant roots too much.
Mix in fresh compost or well-rotted manure to replenish nutrients - about 2-3 inches should be sufficient for most planters. Consider adding organic amendments like worm castings, bone meal, or balanced slow-release fertilizer based on what you're planning to grow. For heavily depleted soil, you might replace up to one-third of the existing soil with fresh potting mix.
Water thoroughly after refreshing to settle the soil and activate nutrients. This annual refresh helps maintain proper soil structure, fertility, and drainage while reducing disease carryover. For container gardens on balconies or rooftops, this seasonal maintenance is particularly important since nutrients deplete faster in confined spaces. With proper soil refreshing each season, your urban planter boxes will continue to support vibrant growth year after year.