Hollyhocks (Alcea rosea) tower majestically at the back of a flowerbed on 4- to 5-foot stalks that bear 3- to 6-inch flowers in shades of white to pink to purple, and even yellow hues. Each flower lasts only a few days, but the season of bloom can be from four weeks to three months long. Hollyhocks require well-drained soil and full sun. While they are sometimes listed as both annuals and perennials, hollyhocks' life cycle is a bit more complex than those categories indicate.
Annual plants go from seed to seed in a single season, dying off at the end of summer. You can plant a seed indoors in pots in late winter or outdoors in early spring and expect to get flowers in the summer. An annual's flowers will then go to seed before fall, if you don't deadhead. Annuals tend to flower all season long because they only have one year to ensure their progeny take hold. In southern climates, most annuals cannot tolerate the heat of summer and are grown as winter annuals instead. Hollyhocks, which only bloom for one summer, are sometimes erroneously considered annuals.
Perennial plants live many years, surviving a winter dormancy period in colder areas and awakening in spring. Herbaceous perennials, such as purple coneflower, die back to the roots when cold weather sets in and then sprout from the roots in spring. Woody perennials, like roses, lose their leaves and flowers but don't die back to the ground. Perennials often do not bloom for the first year or more, instead building up strength to survive the winters before spending energy reproducing. Some woody perennials, such as oak trees, don't bloom for several decades. Because hollyhocks live more than one year, some erroneously categorize them as perennials.
Biennial plants are an intermediary form between annuals and perennials. Biennials spend the first year of their lives building rootstocks and storing energy. Usually biennials grow in a flat circular rosette held near the ground for the first year. After going dormant for the winter, biennials then re-emerge from rootstock, grow a taller flowering structure, set seed and then die. They often flower for longer periods than perennials and manage to set more seeds than an annual because of the energy they accrued over a longer lifetime. Hollyhocks are correctly placed in this category, as they are biennials.
Adding to the Confusion
You often purchase hollyhocks from a greenhouse where they have already gone through a dormant period. If this is your first experience with hollyhocks, you may think of the hollyhock as an annual when it blooms the first summer and dies. In addition, some breeders have developed hollyhocks that will bloom in an extended season, technically more than a natural season, such that if you start them indoors or in a greenhouse they will bloom in one year. Another reason gardeners are confused is that hollyhocks are proficient reseeders. If the seed germinates in two consecutive years, the hollyhock patch will have some second year plants blooming each year. The hollyhock will then appear as a perennial.