Petunias, generally grown as annuals in flower beds and on windowsills of windows and terraces, are in most cases hybrids of horticultural origin, obtained by crossing two species from Brazil. The petunias are divided into four main groups: to the multiflora belong plants thick and 40 to 60 cm high with large leaves and 5 cm wide flowers. The grandiflora is very similar to the previous one, but has fewer flowers that even reach almost double dimensions. The plants belonging to this group are more delicate in the face of unfavorable weather conditions, in particular they are damaged by rain. The other two groups instead consist of dwarf and pendulous varieties. The Petunias should be grown in a light and well-drained soil, in sunny locations. Keep in mind that if the soil is too wet and in the shade, many leaves will be produced, to the detriment of the flowers. The latter are often damaged by wind and intense rain. The petunia is sown in March: the varieties to be grown outdoors will be strengthened in a cold bed before planting them between May and June. Alternatively, bearing in mind the climate of the area, they can be planted directly in March.