For city gardeners, space is a precious commodity. This makes choosing the right planter box size a critical decision. While preferences vary, one size consistently emerges as the most popular and practical choice for urban settings: the 24-inch by 24-inch square box, with a depth of 12 to 18 inches.
This dimension strikes a perfect balance. It offers sufficient soil volume to support a variety of plants—from herbs and lettuces to small tomatoes and flowering annuals—promoting healthy root growth and reducing the frequency of watering. Its footprint is compact enough to fit comfortably on most balconies, rooftops, fire escapes, or small patios without overwhelming the limited area. The square shape also allows for efficient use of space, enabling gardeners to arrange multiple boxes neatly.
The popularity of this size stems from its versatility and functionality. It's large enough to be productive but not so heavy that it becomes immovable when filled with soil. Many urban gardeners find that two or three boxes of this size provide an excellent starter garden. Ultimately, the "most popular" size is the one that best fits your specific space, light conditions, and gardening ambitions, making the 24x24 inch box a reliable and favored foundation for thriving city gardens.