Growing a small salad garden in urban planter boxes is a rewarding way to enjoy fresh greens. The size of your planter boxes is crucial for success. For most salad greens like lettuce, spinach, and arugula, a planter box that is at least 6 inches (15 cm) deep is sufficient. These plants have shallow root systems. However, if you wish to include deeper-rooting vegetables like cherry tomatoes or radishes, opt for a depth of 12 inches (30 cm) or more.
For the length and width, consider the space you have and what you want to grow. A long, narrow planter, about 24 inches (60 cm) long and 12 inches (30 cm) wide, is versatile. It can comfortably accommodate a row of lettuce or a mix of herbs. If space is very limited, several small, square planters (e.g., 12x12 inches) can be used for individual plants.
The key is to ensure your plants have enough room for their roots to spread and access nutrients. Always check the specific requirements for each vegetable or herb you choose. With the right-sized planter boxes, you can cultivate a thriving, compact salad garden on your balcony, patio, or windowsill.