Arranging plants with different sunlight needs in a single urban planter box is a common challenge for city gardeners. The key is strategic placement based on the sun's path across your space. First, identify the sunniest and shadiest sides of your box. Place sun-loving plants like herbs, tomatoes, or succulents on the south or west-facing side where they'll receive the most direct light. Reserve the north or east-facing side for shade-tolerant plants such as lettuce, spinach, or ferns.
Utilize vertical space by employing the "thriller, filler, spiller" method with light in mind. Your tallest "thriller" plant should be a sun-worshipper placed at the back (the sunniest spot). Mid-height "filler" plants can be partial-sun varieties, while trailing "spiller" plants that tolerate some shade can cascade over the shadier side of the box. Consider companion planting; for instance, tall sunflowers can provide afternoon shade for delicate, shade-preferring greens planted at their base.
Regular monitoring is crucial. Observe your box throughout the day and be prepared to rotate it occasionally if possible, or gently prune taller plants to prevent excessive shading. This thoughtful, layered approach ensures every plant gets the light it needs, creating a lush, productive, and harmonious urban garden in a confined space.