When I moved into my first apartment, I planted veggies in the two front window boxes. But I did it pretty willy-nilly, without any research, and some of those poor plants just didn't flourish. If you're thinking of doing the same, please check this out first for some ideas of which plants do best in shallow soils:
The plants listed below do well in shallow soils, shallow being about 12" of depth (or less for the lettuce):
• red radishes
Interested in creating your own window box? Check out this DIY from HGTV. Do remember that plants with shallow root systems have a greater requirement for water, so check often and keep them well-watered!