Most plants in these groups are prized for their showy blossoms. They are able to regrow above-ground parts in spring. Although some perennials can last almost indefinitely, others may last only a few years. You should remember that perennial does not mean perpetual. However, perennials usually can be propagated asexually for additional plants.
Perennials have a shorter bloom period than annuals.
Some will bloom continuously if spent flowers are removed. Others will rebloom later in the same season. In severe winters these plants will not survive. But in mild winters with ideal conditions and sufficient mulch, half-hardy plants will survive. To propagate themselves from year to year, annuals produce great quantities of seeds.