URBAN PLANTER BOXES

You can usually tell an urban planter box is too small by watching both the roots and the top growth. First, check the drainage holes or slide the root ball out after watering. If roots are circling tightly, matting along the sides, or pushing through the drainage holes, the box is restricting them. Next, look at the plant’s mature size: compare its expected root depth and spread with the internal depth and surface area of the box. If the plant’s roots need more than about two-thirds of the box depth, or the mature canopy overlaps neighboring plants, it is too cramped. Watering is another clue. If the soil dries out within a day, water runs straight through, or you are watering much more often than similar plants in larger containers, there is not enough soil volume to hold moisture. Stunted growth, yellowing leaves, few flowers or fruits, and plants that stop growing despite proper light and feeding also suggest a root-bound or under-sized planter. Finally, check spacing: a planter box should give each plant room for its mature spread, not just its seedling size. If you see several of these signs, move up to a larger, deeper box, reduce the number of plants, or switch to compact varieties. In general, shallow boxes suit herbs and lettuce, while fruiting crops such as tomatoes and peppers need deeper soil and more root space.