Zinnia elegans an annual

Annual plant

An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...

 flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 of the genus Zinnia

Zinnia

Zinnia is a genus of 20 species of annual and perennial plants of family Asteraceae, originally from scrub and dry grassland in an area stretching from the American Southwest to South America, but primarily Mexico, and notable for their solitary long-stemmed flowers that come in a variety of bright...

, is the best known Zinnia.

Description

The uncultivated plant grows to about 30 in (76 cm) in height. It has solitary flowerheads about 2 in (5 cm) across on stems resembling daisies

Asteraceae

The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...

. The purple petals surrounding black and yellow discs. The lanceolate leaves are opposite the flowerheads.

Habitat

The native Zinnia elegans is a wild desert plants found in Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

, however garden varieties may escape and naturalise.

Cultivation

The garden Zinnia is derived from hybridisation from the wild form. Zinnias are popular garden plants with hundreds of cultivars, with many flower colors, sizes and forms, including giant forms in which the flowerhead may be up to 6 in (15 cm) in diametre.

Flower colours cover a very wide range range from white and cream, through green and yellow, to apricot, orange, salmon, rose, pink and red, also bronze, crimson, scarlet, maroon, purple, mauve, violet, lavendar and lilac. Some are striped, speckled or bicoloured. The powdery mildew common to Zinnias in humid climates are less an issue among more recent varieties, which are resistant. The flower forms include single, double and semi-double, in addition to single. There are also "pompon" forms that resemble dahlias. Sizes range from dwarf varieties of less than 6 in (15 cm) in height to medium (45-60 cm) up to 3 ft (36 in., 0.75 - 0.9 m) tall.

Other cultivars include Magellan, Envy Double (Chartreuse-Green), Fireworks, Purple Prince, Blue Point Purple, Profusion Cherry, Profusion Orange, Star Gold, Star Orange, while Crystal White, Purity and Profusion White are white varieties. Seeds are often sold as mixtures to produce a rainbow effect, such as Giant Double Mix.

Growth

Zinnias grow easily and prefer loamy soil that is well drained. Exposure should be full sun. Hardy to all zones, they are relatively drought tolerant preferring dry and hot summers and are easily damaged by frost. Seeds should be sown in the spring, after the danger of frost has passed. Alternatively they may be grown indoors, six weeks before the last frost, and then planted out as 6-8 week-old seedlings. However they are very sensitive to transplanting. Although grown as annuals, they may reseed.

Sources

• Floridata: Zinnia elegans
• Dave's Garden: Zinnia elegans
• Plant of the week: Zinnia elegans
• Garden Guides: Zinnia elegans
• Wildflower Information: Zinnia elegans
• North Carolina State University: Zinnia elegans
• Flowers of India: Zinnia elegans

Cultivars

• Martha Stewart: Zinnia elegans 'Purity'