Depending on where you live, some herbs are perrenial and will grow back each year. Even in Brooklyn, sage, thyme, lavendar, mint and oregano would grow back each year. But rosemary never really made it. And softer plants like basil, parsley, dill, cilantro, had shorter life cycles so I planted lots of seeds.
I have to say… It was frustrating to NOT have rosemary in the spring. I liked a lot of it, and it could be expensive buying a dozen mature transplants. So about this time of year, I would start creating my own rosemary plants. Not from seed, though, because like I mentioned, that takes FOREVER!