Chrysanthemum

Revision as of 21:58, 29 January 2009 by Raffi (talk | contribs) (→‎Cultivation: added section from AHS)


Maroon Mum


Plant Characteristics
Lifespan: perennial
Origin: Asia, NE Europe
Cultivation
Exposure: full sun"full sun" is not in the list (sun, part-sun, shade, unknown) of allowed values for the "Exposure" property.
Water: regular"regular" is not in the list (wet, moist, moderate, dry, less when dormant) of allowed values for the "Water" property.
Features: flowers
Sunset Zones: see species
Scientific Names

Asteraceae >

Chrysanthemum >


There are about 160 species of Chrysanthemum, so the genus is very broad. Most of the ones we know are of the species C. morifolium, better known as Florists' Chrysanthemum. These bloom in autumn, are the most useful, with a rainbow of colors and flower forms, as well as growth habits. The flowers are good cut flowers as well. The Shasta Daisy (C. maximum) is another popular species that is a heavy summer and fall bloom of white flowers with gold centers, with varying flower forms. The number of cultivars is probably countless, and growing quickly. Below is a general breakout of the many types into groupings which will simplify how to care for them.

The species of Chrysanthemum are herbaceous perennial plants, with deeply lobed leaves and large flowerheads, white, yellow or pink in the wild species.

Garden Chrysanthemums

 
Cultivated chrysanthemums can be yellow, white, or even bright red, such as these.

These have a bushy, branched habit. Clusters of flowerheads come in a large variety of colors. They are divided into two loose categories, garden types, which tend to the upright, and cushion, which is more of a mound. Flowers come over a long period, usually during early or midseason They are suitable for annual or herbaceous borders. C. segetum works well in wildflower gardens as well.

Exhibition Chrysanthemums

Disbudded

Non-disbudded

Rubellum Group Chrysanthemums

Perennials. Bushy and clumping. All are hybrids of C. rubellum (syn. Dendranthema zawadskii). Leaves are pinnatisect, frequently silvery. Flowerheads come in a range of colors, all with a yellow center. They may be single, semi-double or double. Flowers from late summer to early fall. Great as cut flowers, and in herbaceous borders.

Cultivation

Early and mid-season flowering mums grow outdoors in sheltered spots. They like full sun, fertile soil, which is moist but drains well, neutral (or slightly acidic) pH, with well rotted manure. Balanced fertilizer should be used on the soil in a top-dressing before planting them, which should only be done after any chance of frost has passed. As it grows, provide support if necessary, tying with soft twine as it grows. Eventual height can vary widely, depending partly on pruning and fertilization. Plants can be stopped at 6-8 inches (15-20cm) to help encourage flowering lateral production. Stopping those laterals again will encourage an even larger number of blooms, although they'll be smaller. If you want exhibition type blooms, only allow the right number of strong flower stems to remain. Gradually remove undesirable buds, as laterals reach 3/4 in (2cm) in length. The timing of all of this depends on how quickly the plant is growing, but a rule of thumb is to stop all of the disbudding/stopping by July 15 in cooler climates and by July 25 in warmer.

Water freely when conditions are dry. Give balanced fertilizer once a week to a week and a half from mid-summer to when the buds start showing color. When flowers are past their prime, cut back their stems to 6-9 inches (15-23cm). In cooler climates, dig up the crowns and store them in a frost-free place, in soilless potting mix. In warmer climates, apply a thick layer of dry mulch before winter, and in early spring cut back the plant. Early and mid-season exhibition cultivars should be protected from frost and rain. These types are best grown in a cold greenhouse or an open-sided plastic-covered lath house, and the same is true for large-flowered exhibition cultivars.

Late flowering exhibition chrysanthemums, which include the charms, cascades and late flowering sprays all do best in a porous soil-based mix that is slightly acidic, and has added manure. Grow in 3 in. (7.5cm) pots and continually repot into larger sizes until they flower in 9-12 inch (25-30cm) pots, supported with stakes. Do not disbud plants until a week and a half after repotting. Begin growing in a cold frame, then move into warm greenhouse early in the fall, providing adequate air ventilation and always maintaining the temprature above 50F (10C). Water moderately beginning in mid-summer on, and give a balanced fertilizer weekly.

Rubellum Group and annual mums should be grown in full sun, in well drained soil which is moderately fertile.

Propagation

Plant seeds of plants in the charms and cascades groups of Chrysanthemums in late winter to spring at 55-61F (13-16 C). Rubellum group should be sown at the same temperatures in the spring, or by division in fall or early spring. In colder climates sow the seeds of annual types in a cold frame during early spring or in situ in spring to early summer, and in mild climates sow them in situ during autumn for them to bloom early early in the season the next year.

Exhibition types which are overwintered can be used to get basal cuttings - for those that are late flowering take the cuttings in early to mid-winter. All other types of Chrysanthemum cuttings can be taken early in spring. Root cuttings at 61F (16C) in a sandy potting mix, preferably soilless. Protect from cold, in cold frame if necessary. Maintain ventilation if possible. Hardening is possible beginning in mid-spring.

Pests and diseases

Susceptible to aphids, earwigs, nematodes, capsid bugs, leaf miners, whiteflies, fungal rot, gray mold (Botrytis), powdery mildew, white rust, and viruses. Viruses can result in puckering of the leaves, yellow marks or stunt the growth. Used as food plants by the larvae of some Lepidoptera species — see list of Lepidoptera which feed on Chrysanthemum.

Species

The genus once included many more species, but has been split. The defining species, Chrysanthemum indicum, was also changed, then changed back after much controversy thereby restoring the economically important florist's chrysanthemum to the genus Chrysanthemum. These species were, after the splitting of the genus but before the ICBN ruling, commonly treated under the genus name Dendranthema.

The other species previously treated in the narrow view of the genus Chrysanthemum are now transferred to the genus Glebionis. The other genera split off from Chrysanthemum include Argyranthemum, Leucanthemopsis, Leucanthemum, Rhodanthemum, and Tanacetum.

About 160 species, including:

Sortable table
Latin Synonyms Common names USDA Zones Sunset Zones
Chrysanthemum aphrodite x none 0 na
Chrysanthemum arcticum Arctanthemum arcticum none 0 1-24, 32-45
Chrysanthemum argyrophyllum x none 0 na
Chrysanthemum arisanense x none 0 na
Chrysanthemum balsamita Tanacetum balsamita Costmary 0 2-24, 28-41
Chrysanthemum boreale x none 0 na
Chrysanthemum chalchingolicum x none 0 na
Chrysanthemum carinatum x Summer Chrys., Tricolor Chrys. 0 All zones
Chrysanthemum chanetii x none 0 na
Chrysanthemum cinerariaefolium x none 0 na
Chrysanthemum coccineum Pyrethrum roseum, Tanacetum coccineum Pyrethrum, Painted daisy 0 2-24, 33-41
Chrysanthemum coronarium x Crown daisy 0 All zones
Chrysanthemum crassum x none 0 na
Chrysanthemum frutescens Argyranthemum frutescens Marguerite, Paris Daisy 0 14-24, 26, 28
Chrysanthemum glabriusculum x none 0 na
Chrysanthemum hypargyrum x none 0 na
Chrysanthemum indicum x none 0 na
Chrysanthemum japonense x none 0 na
Chrysanthemum japonicum x none 0 na
Chrysanthemum lavandulifolium x none 0 na
Chrysanthemum leucanthemum Leucanthemum vulgare Ox-eye Daisy, Common Daisy 0 1-24, 28-43
Chrysanthemum mawii x none 0 na
Chrysanthemum maximowiczii x none 0 na
Chrysanthemum maximum C. superbum, Leucanthemum maximum Shasta Daisy 0 1-24, 26, 28-43
Chrysanthemum mongolicum x none 0 na
Chrysanthemum morifolium Dendranthema grandiflorum Florists' Chrysanthemum 0 2-24, 26, 28-41
Chrysanthemum morii x none 0 na
Chrysanthemum multicaule Nipponanthemum nipponicum none 0 2-24, 29-41
Chrysanthemum okiense x none 0 na
Chrysanthemum oreastrum x none 0 na
Chrysanthemum ornatum x none 0 na
Chrysanthemum pacificum Pyrethrum marginatum, Dendranthema pacificum Gold and Silver Chrys. 0 2-24, 28-41
Chrysanthemum paludosum Leucanthemum paludosum none 0 All (annual)
Chrysanthemum parthenium Tanacetum parthenium Feverfew 0 1-24, 28-45
Chrysanthemum potentilloides x none 0 na
Chrysanthemum ptarmiciflorum Tanacetum ptarmiciflorum Dusty Miller, Silver Lace 0 16, 17, 19-24 (all as annual)
Chrysanthemum rubellum Dendranthema zawadskii none 0 1-24, 28-43
Chrysanthemum segetum x none 0 na
Chrysanthemum serotinum C. uliginosum none 0 2-9, 14, 28-43
Chrysanthemum shiwogiku x none 0 na
Chrysanthemum sinuatum x none 0 na
Chrysanthemum vestitum x none 0 na
Chrysanthemum weyrichii Dendranthema weyrichii none 0 2-6, 32, 34-41
Chrysanthemum yoshinaganthum x none 0 na
Chrysanthemum zawadskii x none 0 na

Gallery

References

External links