Herbs are good plants for roof top gardening, as they are so tough and stay ready for picking when needed.
On my rooftop terrace in inner city Sydney I grew them in big pots and troughs across the open North side, I had oregano, salad burnet, and parsley, lemon grass, thyme and chives, rosemary, and sage. In smaller pots against the East facing wall I grew mint, basil and coriander. The first eight are set and forget plants; the oregano seeds and spreads from year to year, and the salad burnet needs a complete chop back in winter to thin it out a bit. The sage sulked a bit in winter, and I think the secret to growing it and chives in Sydney is to mix up a sandy potting soil.
For annual herbs, I find the best way to grow basil is to buy one of the cheap pots of seedlings from the green grocer and pot into a large container. They are very crowded but do fine and grow very quickly into enough to pick, and they tend to last well into winter. Coriander grows easily from a few of the spice seeds from the kitchen, although if you have seeds of a herb cultivar, so much the better. Seeds planted in March or April (Autumn) do well, as they go to leaf in the shortening days. Seeds planted in long days tend to bolt to flower without making much leaf, which is a pity because it’s really summer when I want coriander leaves for Thai style meals. It’s easy to buy, though.
For mint I grew the long, dark green and shiny – leafed spearmint. It needs two types of attention. Firstly it gets leggy, and responds well to complete cutting back. Be brave and it will send up thick new shoots from the underground runners. Secondly, it is plagued by green caterpillars. I would sit and try to remove every one, after all it was not a big pot, but they are hard to see and they would always end up completely stripping the leaves (a good time to chop back to ground level). The best solution has been the B. thuringensis biological warfare spray. You buy it as packets, expensive but it lasts, mix it with water, and spray. It kills every little invisible grub and is otherwise harmless.
Thyme, chives and lemongrass growing in a large pot in full sun and wind.