Many people are confused about whether dill is a perennial or an annual. Dill is technically a biennial plant, which means that it has a two-year life cycle. However, the first year of its life cycle is spent as a rosette and therefore not producing any flowers or seeds. Therefore most the time the dill plant is an annual, meaning that it will only grow for one year. However, you can save the seeds from the plant and grow them again next year. However, It can be grown in pots and then moved indoors during the winter months.