Chiba University Matsudo/Kashiwa Campus Plant Database

Details of genus: Dahlia Cav. [336]

genus_ja: ダリア

genus_en:

# spp.: 41

pub_year:

accepted: Accepted

Family: Asteraceae

family_ja: キク

Infra familial classification: Subfamily Asteroideae: Tribe Coreopsideae

distribution_en: Mountains of Mexico to Columbia

description_en: Genus of about 30 species - and some 20,000 cultivars, predominantly derived from D. pinnata and D. coccinea - of bushy, usually tuberous-rooted perennials from mountainous areas of Mexico and Central Anerica. The mid-to dark green leaves, 20-50cm (8-20in) long, are usually pinnate, the toothed, oval leaflets having rounded tips, or are sometimes pinnatifid to pinnatisect. Dahlias are grown for their flowerheads, cultivated in a variety of forms (see panel below), and in colours from white to red, orange to yellow, and pink to dark purple. They flower from mid-summer to autumn (until the first frosts in cool-temperate regions), when many other plants are past their best. Although often informally divided into 2 types - tall-growing "border" dahlias and low-growing "bedding" dahlias - all are good for garden display and cutting. Many, especially the giant-flowered dahlias, are also suitable for exhibition. Bedding dahlias, which may be raised from seed and treated as annuals, flower from early or midsummer to autumn, particularly if dead-headed, and are suitable for massed plantings, for edging a border, or for growing in a container. Those grown for exhibition or cutting look best in rows on their own, free from competition with other plants. Most dahlias are classified according to the form of their flowerheads. In addition, the groups most commonly grown for exhibition are classified by the width of the flowerhead (see table below), although the precise dimensions may vary according to the specifications of the various national dahlia societies.

hardiness_en: Frost hardy to frost tender.

cultivation_en:

propagation_en: Sow seed of bedding dahlias in trays at 16°C (61°F) in early spring; harden off and plant out when all danger of frost has passed. Take basal shoot cuttings from tubers started into growth in late winter or early spring under glass, and root in propagating case. Alternatively, start tubers into growth in early spring and, when shoots are 2cm (3/4in) long, divide tubers into 2 or 3 pieces, each with a shoot; plant these out, 12cm (5in) deep, after all danger of frost has passed.

pests_en: Aphids, capsid bugs, red spider mites, caterpillars, earwigs, and slugs may be troublesome. Also prone to powdery mildew, mosaic virus, tomato spotted wilt virus, and rotting of tubers in store.

description_ja:

comment:

comment_ja: 別名　テンジクボタン

type_species:

Phylogenetic definition:

Update Information: Created: 2007-12-06 12:51; Updated: 2023-06-28 16:35 by hkokubun@mac.com

family: