For a kitchen balcony, I’d suggest a compact, rectangular self-watering planter box as your best all-round choice. Look for one that is about 24 to 30 inches long, 10 to 12 inches wide, and at least 7 to 8 inches deep. That gives herbs like basil, parsley, mint, chives, and thyme enough room to grow without taking over the balcony. A self-watering reservoir is especially useful in a kitchen setting because it reduces how often you need to water, and it helps keep herbs from drying out on hot days. Just make sure the planter still has proper drainage holes and a saucer or tray to protect your balcony floor.
Choose a food-safe material that suits your space. Lightweight, UV-resistant plastic is practical and easy to move, while glazed ceramic looks nicer but can be heavy. Powder-coated metal and cedar are also good options if they are designed for outdoor use. If your balcony is windy or you plan to place the box on a railing, choose a railing planter with strong adjustable brackets, or use a floor-standing planter with casters so you can move it easily. Avoid very shallow boxes, because herbs need decent soil depth to develop healthy roots.
Also think about sunlight. Most cooking herbs need four to six hours of sun, so place the planter where it gets good morning light and some afternoon shade if your balcony gets very hot. If space is tight, a two-tier or modular vertical planter can double your growing area without blocking the walkway. For a simple, productive kitchen balcony setup, I’d start with one well-drained self-watering rectangular box for larger herbs and add a small railing or vertical planter later for mint, chives, and other compact varieties.