Chrysanthemum

CHRYSANTHEMUM, in botany, a numerous genus of plants of the family Compositae ; popularly the name given to forms of certain Old World species of this genus which have been remarkably developed by cultivation. Most varieties of the so-called Chinese and Japanese chrysanthemums extensively grown by gardeners and florists are blended hybrids or other forms derived from C. mori f olium and C. indicum, natives of eastern Asia. Other species of interest to flower growers are C. coccineum (pyrethrum), C. Parthenium (feverfew), and C. frutescens (mar guerite). Other representatives of the genus are C. Balsamita (costmary) and C. Leucanthemum (ox-eye daisy), the latter often a pestiferous weed. The common chrysanthemum has prob ably been known for at least 2,000 years. In Japan, where it can be traced back many centuries, it is the national flower. Brey nius in 1689 was the first European to mention the chrysanthe mum, giving it the name of Matricaria Japonica Maxima. M. Pierre Louis Blancard introduced the first large-flowering chrysan themum into England in 1789. This first flowered in 1790. The plant was first introduced into America in 1847. The work of hybridization was first taken up by Dr. H. P. Walcott and later in the '8os by John Thorpe, who organized the Chrysan themum Society of America in 189o, at which time hybridization seemed to have reached its zenith. At the present day (1929) Elmer D. Smith is probably the leading hybridizer of the chrysan themum.

Chrysanthemums have been popular with the gardeners, both professional and amateur, as an exhibition flower because of their great size and variety of shape and colour, and also because some varieties are extremely hardy permitting their use in the peren nial garden. Chrysanthemums owe their popularity with com mercial florists not so much to their value as a crop, but to the fact that they may be planted in the late spring and early summer when the greenhouse otherwise would be empty. Moreover, the chrysanthemum is a quick maturing crop, many varieties being grown without artificial heat, since they bloom from late August to December. The cultural requirements for chrysanthemums may be adjusted to many rotation schemes, so that the same greenhouse may be used for growing other floral crops, as calen dulas, sweet-peas, stocks, snapdragons, annuals and lilies.

Classification of Types.

(I) Incurved Chinese types are nearly globular in form and regular in outline; the florets are smooth, rounded or somewhat toothed at the top, and sufficiently long to form a graceful curve (commercial varieties are Ma j. Bonaffon, Mrs. Nellie T. Ross, Citronelle). (2) Japanese types are varieties with long loosely arranged florets; the florets may be flat, fluted, quilled or tubulated, and may be incurved or reflex. Many exhibition varieties (Mrs. H. S. Firestone, F. E. Nash, Miss Ruth C. Twombly, Majestic) come in this type. (3) Anemones have high, neatly formed centres with elongated quilled florets, surrounded by flat more or less horizontally arranged ray flowers. Examples are: Gorza, Chestnut, Maple-leaf. (4) Pom pons may be somewhat flat or nearly globular, generally very neat and compact, formed of short, flat, fluted or quilled florets. The florets of each bloom are all of one form, such as the varieties Varsity, Co-ed, Baby, Pink Dot and Nuggets. (5) Singles are arranged sufficiently close together to form a regular fringe. There may be one or two rows of ray flowers and sometimes as many as three or five. The centres of the florets are always tubu lar, either short or somewhat elongated. Golden Mensa, Mrs. E. D. Godfrey and Margaret Waite are good examples. (6) Spidery, plumed and feathery types are varieties with flowers of eccentric shape ; some are light and graceful, while others have threadlike petals. Among the varieties of this class are the Dean, Yellow Jacket, Chief, Sam Caswell, Tachibana and White Thread.

Propagation.

The chrysanthemum is generally propagated by cuttage, seedage or division. Cuttage is by far the most satis factory. Most of our destructive insects and diseases may be controlled by the careful selection of clean stock to be used for cuttings. Plants grown from cuttings make better growth, give better flowers and are easier to stake and tie in the garden. Nearly all chrysanthemums grown in commercial greenhouses are pro duced from cuttings. Division is practised by many outdoor gardeners. The only advantage is that the operation is an easy and safe one, but diseases and insects are generally spread with this method. Seedage is practised in chrysanthemum growing only as a means of obtaining new varieties.

Plants for propagation are packed close together in flats, benches or cold frames after the flowering season, and are wintered over in either a cold greenhouse or frame. In March or April these plants send up strong shoots which are ideal for making cuttings. A cutting from 2 to 4 in. long seems to be best. As soon as the cuttings are made they should be placed in cool water. If aphids are present, the cuttings should be placed in a 1 to 500 or 1 to Boo solution of nicotine sulphate in water before planting. Clean sand is the best soil material in which to root such cuttings. The sand should be firmly packed and watered and the cuttings in serted. They should then be firmed and watered to wash the sand down around them. The bed should be lightly shaded for a few days to prevent wilting. Wilted cuttings generally die but if they root the resulting plants are stunted. Syringing on warm days will help to keep the cuttings fresh. A temperature of 5o° F is sufficient, but quicker rooting is obtained if 6o° F is maintained.

When the roots are about - in. long the plants should be potted in a fibrous loam soil. If allowed to remain too long in the cutting bed, they become hard and are not responsive to good culture. The plants are usually ready for their permanent quarters by early June or July. A good fibrous, well drained loam is the ideal soil medium for chrysanthemums. If this soil is packea before planting or directly afterwards, the new growth becomes firmer and the internodes shorter. Newly set plants should be watered only lightly as wet soil is unfavourable for their growth. The tops of the plants may, however, be syringed often to keep them fresh. The planting distances vary with the different types. Commercial growers vary the planting of the large flowering chrysanthemums as follows: 6 in. by 6 in., 7 in. by 8 in., 71 in. by 8 in., 10 in. by io inches. Pompons are planted 12 in. by 12 in. and 12 in. by 15 in. inside, while outdoors 15 in. by 15 in. and 18 in. by 18 in. is the general practice.

As soon as the plants are placed they should be staked and tied. The tying should be done as the plant grows so the stem will remain straight. When the stem becomes 6 in. long the plant should be "topped" (top pinched out), if more than one stem is desired. Topping should continue for small flowered plants until August. Watering, syringing and tying are of chief importance during the summer months. The plants should be kept as cool as possible by spraying and syringing and by wetting the walks. In the late summer and early fall "disbudding" becomes a factor. The first bud to appear is generally the crown bud. This bud will flower early and give a large flower, but the shape, colour and habit are not as desirable for commercial use as are flowers from lateral buds. The crown bud is surrounded by vegetative shoots. one of which may be saved to produce the desirable flower bud. The terminal bud of the final shoot is surrounded by other buds which should be removed if only one large flower is desired.

If the soil is a good composted fibrous loam, no fertilizer should be given until the bud is selected. Thereafter manure water, a commercial chrysanthemum fertilizer, should be given once a week until the buds show colour. Continued use of any fertilizer, especially those that are too strong, will cause the flowers to "blast" and "burn." The foregoing cultural directions apply equally as well to the chrysanthemums in the garden. Systematic fumigation and spraying with effective fumigants, insecticides and fungicides and the propagation of clean stock, are the greatest factors in the prevention and control of pests. Upwards of 50o named varieties of the chrysanthemum are listed in dealers' catalogues and horticultural works, and new forms are constantly being produced.

For more extensive details,

see L. H. Bailey, The Standard Cyclo pedia of Horticulture (1914-17 ; rev. ed., 1922) ; for list of recognized American varieties, see F. L. Olmsted, F. V. Coville and H. P. Kelsey, editors, Standardized Plant Names (Salem, Mass., 1924) . See also E. A. White, The Chrysanthemum and Its Culture (193o). (H. O. Y.)