Gardening FAQ

The classification of mums is rather complicated.  The Chrysanthemum genus includes many well-known flowers such as shasta daisy, ox-eye daisy, pyrethrums, marguerites and Paris daisies, and annual species, but most people think only of garden or florist mums as “chrysanthemums”.  Chrysanthemums are also classified according to when they flower, and this criterion also determines whether they are suitable for outdoor culture in temperate regions. Early-flowering mums are defined as those that are grown in the open and flower before early October. Late-flowering mums are those that flower in November and December and flower in the greenhouse.  Most of the exhibition-type mums fall under this category.  The first category can also be considered to be “hardy mums” and can winter over outside in northern climes, but not always.  Commercial growers can provide chrysanthemum flowers at any time of the year. They can do this mainly by manipulating the hours that the plants are exposed to light and temperature. Note that the chrysanthemums that are widely available in the fall tend to be annuals and will not survive the winter outdoors in the Northeast. The University of Minnesota has developed a number of very cold-hardy varieties; the can usually be recognized by having “minn’ or “sota” in their names, e.g. ‘Minnautumn’ or ‘Lemonsota’

The National Chrysanthemum Society (U.S.A.) classifies mums into 13 groups based on the forms of their blooms and florets:

Class 1: Irregular incurve

Class 2: Reflex

Class 3: Regular incurve

Class 4: Decorative

Class 5: Intermediate incurve

Class 6: Pompom

Class 7: Single and semi-double

Class 8: Anemone

Class 9: Spoon

Class 10: Quill

Class 11: Spider

Class 12: Brush and thistle

Class 13: Unclassified types

For detailed descriptions of these National Chrysanthemum Society classifications, visit Chrysanthemum Classes. (The British chrysanthemum society uses a slightly different classification system.)

Other terms for chrysanthemum types can also be encountered, e.g.:

Korean mums:  This refers to a group of hardy strains of single and doubles derived in the U.S. from a species originating from Korea (probably Chrysanthemum zawadskii). They are very hardy and free-flowering.

Rubellum mums: These are very similar to Korean mums and may be a related cultivar developed independently in the U.K. They are cold-hardy. Popular varieties include: “Clara Curtis’, “Mary Stoker’ and “Duchess of Edinburgh’.

Belgian Mums®: These are trade-named varieties registered to the Gediflora Company (Belgium). They are usually hardy.

Charm mums: These are bushy, dwarf and rounded in habit and grown for indoor decoration or exhibition.  They are not pruned or shaped.

Cascade mums: These flowers are similar to charms but are trained into different shapes.

Kiku: This is the Japanese word for chrysanthemum. Japanese kiku cultivation has developed into a complex art form. For more information, see our answer to the question, What is kiku?

For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service