Chrysanthemums are usually considered herbaceous perennials. However, if you wish to grow chrysanthemum plants in your area as perennials, select an appropriate cultivar (which, in cold climates, will mean one of the hardy mums).
The following post was submitted by Greenstreet Garden staff member Maggie Wiles.
The name "chrysanthemum" is derived from the Greek words, chrysos (gold) and anthemon (flower). Modern cultivated chrysanthemums are much more showy than their wild relatives. The flowers occur in various forms, and can be daisy-like, decorative, pompons or buttons. This genus contains many hybrids and thousands of cultivars developed for horticultural purposes. In addition to the traditional yellow, other color are available, such as white, purple, and red.
Chrysanthemums were first cultivated in China as a flowering herb as far back as the 15th century BC. Chrysanthemum flowers have traditionally been boiled in China to make a tea, used in folk medicine for influenza patients. Chrysanthemum cinerariaefoliu, or Pyrethrum, is economically important as a natural source of insecticide as well as an insect repellent.
In landscaping, chrysanthemums are valued for the fact that they bloom in fall; helping you to achieve four-season interest in your yard—they've become a staple for outdoor fall decorating.
Plant in full sun and well-drained soil, enriched by compost. Chrysanthemums are "photoperiodic"; i.e., they bloom in response to the shorter days and longer nights experienced (in the Northern Hemisphere) in fall.
Also, don't overcrowd chrysanthemums: good air circulation reduces the chance of disease.