This will depend on the sunflower variety that you choose to grow. Some types of sunflowers are perennial and they will regrow without your help, while other types are annual and will require that you replant them each season. If you’re unsure how to tell a perennial sunflower from an annual sunflower, look for these key differences: • Annual sunflowers feature a lot of large seeds, while non-hybridized perennial sunflowers feature a modest amount of small seeds. • Annual sunflowers feature shallow roots that look like strings, while perennial sunflowers feature long roots with rhizomes and tubers attached to them. • Annual sunflowers grow on a single stem, while perennial sunflowers grow in a cluster formation. • Annual sunflowers have seed heads that are large or small, while perennial sunflowers only have small seed heads. • Annual sunflowers produce blooms the first year their seeds are planted, while perennial sunflowers do not produce blooms until two years after their seeds are planted. • Annual sunflowers sprout and grow quickly, while perennial sunflowers sprout and grow slowly. • Annual sunflowers sprout in late spring, while perennial sunflowers sprout in early spring.