Growing your own lettuce in urban planter boxes is a rewarding way to ensure fresh, weekly salads. The number of boxes you need depends on a simple calculation. First, consider that a standard small salad requires about 2-3 mature lettuce leaves per person. A single lettuce plant, like loose-leaf varieties (e.g., Black Seeded Simpson, Oakleaf), can provide multiple harvests through the "cut-and-come-again" method.
A typical 24-inch long by 12-inch wide planter box can comfortably support 4-6 lettuce plants with proper spacing (about 4-6 inches apart). Each plant can yield roughly 1-2 harvestable outer leaves per week once established. Therefore, one well-maintained planter box of this size can produce enough for one substantial single-person salad per week.
For a consistent weekly salad for one adult, we recommend starting with 2 planter boxes. This allows for a staggered planting schedule. Plant one box every two weeks. This succession planting ensures a continuous supply, accounts for slower growth periods, and provides a buffer. With two boxes in rotation, you'll always have fresh lettuce ready for harvest.
Key factors influencing yield include sunlight (at least 6 hours), consistent watering, using nutrient-rich potting mix, and choosing high-yielding, continuous-harvest varieties. Remember, container-grown plants need more frequent watering than in-ground gardens. With just a couple of boxes, you can enjoy the satisfaction of homegrown greens and elevate your weekly meals with minimal space.