Absolutely! Growing root vegetables like carrots in urban planter boxes is not only possible but can be highly rewarding. The key to success lies primarily in providing sufficient depth for the roots to develop properly. For most standard carrot varieties, your planter box should be at least 12 inches (30 cm) deep. For longer varieties, such as 'Imperator,' aim for containers 16 to 24 inches deep.
Beyond depth, choose a loose, well-draining potting mix free of stones and clumps to prevent forked or stunted roots. Ensure your planter box has adequate drainage holes. Select shorter or "round" carrot varieties like 'Parisian' or 'Chantenay' for shallower boxes. Place your planter in a location that receives full sun (6-8 hours daily). Keep the soil consistently moist, and thin seedlings early to prevent overcrowding. With the right depth and care, you can enjoy sweet, homegrown carrots from your balcony, patio, or rooftop.