Basil will keep growing until it produces seeds, as it is an annual. Keep the flower heads picked and a plant usually will grow for a year or two before you need to plant a new one indoors. In the garden, I grow it as an annual and freeze any I can’t use up.

Parsley is a biennial. Grow it as an annual for best flavor whether indoors or out. When the first flower stalks start to form, plant new ones and ditch the old ones, as they get bitter once they shift gears towards reproduction.

Oregano is a perennial. If you take good care of it you should get at least five years of good growth indoors, and if you have a garden it will last nearly indefinitely as it self-sows and spreads like crazy (give it lots of room!)