Marigold is very popular amongst the gardeners and florists because of its easy culture and wide adaptability. Its habit of free flowering, short duration to produce marketable flowers, wide spectrum of attractive colour, shape, size and good keeping quality attracts the attention of flower growers. In India, it is one of the most commonly grown flowers and extensively used in religious and social functions, in one form or the other, ego garlands or loose form.
It has been established that marigold is native of Central and South America especially Mexico. From Mexico it spread to different parts of the world during early part of the 16th century. African marigold was first introduced into Spain and became popular in southern Europe, under the name "Rose of the Indies". The name Tagetes was given after Tages, a demigod, known for his beauty. Marigold is also known as "friendship flower" in United States.
Marigold requires mild climate for luxuriant growth and flowering. In very high temperature, plants ceases to grow, flower production is affected adversely and flower size is also reduced to a great extent. During severe winter, plants and flowers are damaged by frost. Therefore, depending on environment, planting is done in three seasons i.e. rainy, winter and summer; and seeds are sown accordingly. Hence, flowers of marigold can be obtained during larger part of the year.
The environmental conditions after the seedlings are transplanted markedly influence the growth and flowering. Mild climate during growing period (14.5 -28.6 °C) greatly improves flowering while higher temperatures (26.2 -36.4°C) adversely affect flower production.
Marigold is adaptable to different types of soil conditions and thus can be grown successfully in a wide variety of soils. However, a deep, fertile, friable soil having good water holding capacity, well drained and near to neutral soil reaction (PH 7.0 -7.5) IS most desirable. An ideal soil for marigold cultivation is fertile sandy loam.
The important species are described here in detail.
There are about 33 species of the genus Tagetes. The characters of important species are given here.
The plant is hardy, annual, about 90 cm tall, erect and branched. Leaves are pinnately divided and leaflets are lanceolate and serrated. Flowers are single to fully double and large sized of globular heads. The florets are either 2-lippedor quilled. Flower colour varies from lemon-yellow to yellow, golden yellow or orange.
A hardy annual, about 30 cm tall forming a bushy plant. Foliage is dark green with reddish stem. Leaves are pinnately divided and leaflets are linear lanceolate and serrated. Flowers are small either single or double, borne on proportionately long peduncles. The flower colour varies from yellow to mahagony red.
It is dwarf annual with a branching habit. It is bushy and grows less than 30 centimeters. Leaves are pinnately divided into 12 oblong linear, sharply serrated segments. Flowers have 5 rays, yellow roundish and obovate. Flowers are bright yellow and small but numerous.
The plants of this species are tender perennial. Leaves are sessile, small and lanceolate. Flowers usually are 2-3 rayed, produced in dense, terminal corymbs. The flowers have much more agreeable odour than other species.
It was discovered in California. The plant grows up to 120-150 cm in height and flowers profusely. Flowers are yellow in colour.
It is a shrubby plant, grows up to 60-70 cm. Leaves are slender, opposite, leaflets about 2-3 cm long. Flowers are showy and 2-3 cm in diameter.
The other species grown in gardens are T.minuta, T.pusilla and T.corymbora. In India, however, the cultivation of T.erecta and T.patula dominates.