Yes, an urban planter box on your balcony can attract bees and wasps, but it is not automatic. The main factor is what you plant. Bees are usually looking for nectar and pollen. If your planter box contains flowering herbs, fruits, or ornamentals, especially ones with open, daisy-like, tubular, or brightly colored blooms, bees may find them, even several floors up. Wasps also visit flowers for nectar, but they are often more interested in sugary drinks, fallen fruit, food scraps, and protein sources. A planter box itself is rarely the attraction; the flowers, soil, moisture, and nearby food or nesting sites are.
Balcony height matters. A high balcony may get fewer ground-nesting bees and some wasps, but honeybees, bumblebees, and paper wasps can fly up easily. Wind, sun, and surrounding trees or other balconies also affect traffic. If you grow plants that need pollinators, you may actually benefit from bee visits. Beans, tomatoes, peppers, strawberries, lavender, rosemary, basil, and many other balcony crops can produce better with pollinators around.
To reduce bees and wasps, avoid heavy flowering plants during peak season, choose wind-pollinated grasses or foliage plants, deadhead flowers promptly, and keep the area free of open sugary drinks, ripe fruit, pet food, and uncovered garbage. Fix dripping taps or standing water, because wasps need water and may nest near damp shelter. Check eaves, railings, and planters for paper-like nests. If you find a nest and it is far from your door, you can often leave it alone; if it is a danger, call a professional.
To attract them intentionally, plant nectar-rich flowers like calendula, cosmos, borage, salvia, and native wildflowers, and provide a shallow water dish with stones. Either way, a balcony planter box can be a small habitat. The key is matching your plant choices and balcony habits to the kind of wildlife you want to see.