Petunia, in botany, a genus of plants belonging to the natural order Solanaceae and containing about 16 species, chiefly South American (southern Brazil and Argentina). The garden forms are derived from the white-flowered P. nyctaginiflora and the violetor purple-flowered P. violacea. The varieties of petunia, especially the double forms, make admirable specimens for pot culture.
Named or specially fine varieties are propagated by cuttings taken from stock plants kept through the winter on a dry warm shelf, and moved into a brisk moist heat in early spring; the young shoots are planted in pans or pots filled with sandy soil, and, aided by a brisk bottom heat, strike root in a few days. They are then potted singly into thumb-pots, and when once established are gradually hardened off, and afterwards repotted as required. The shoots should be topped to make bushy plants, and their tops may be utilized as cuttings. The single varieties are raised from seeds sown in light sandy soil in heat, in the early spring, and very slightly covered. The plants need to be pricked out or potted off as soon as large enough to handle. Good strains of seeds supply plants suitable for bedding; but, as they do not reproduce themselves exactly, any sorts particularly required must be propagated, like the double ones, from cuttings.
