Determining whether your urban planter boxes receive sufficient sunlight is crucial for the health of your plants. Start by researching the specific sunlight requirements for each plant variety you've chosen, typically categorized as full sun, partial sun, or shade. Observe your planter's location throughout the day, noting how many hours of direct sunlight it receives. Morning sun is generally less intense than afternoon sun, which can be important for more delicate plants.
Use the shadow test: place your hand where your plants are located and observe the shadow clarity. A crisp, well-defined shadow indicates direct sunlight, while a fuzzy shadow suggests indirect light. Consider seasonal changes - a spot that gets full sun in summer might be shaded in winter due to the sun's lower angle.
Monitor your plants for signs of insufficient light, including leggy growth, leaning toward light sources, pale leaves, or reduced flowering. Conversely, signs of too much sun include scorched leaves or wilting during peak hours. If natural light is inadequate, consider supplementing with grow lights or relocating your planters to optimize their exposure. Remember that reflected light from buildings can sometimes provide additional illumination in urban environments.