Petunia

Petunia is a genus of flowering plants in the nightshade family (Solanaceae). It comprises about 20 species native to the tropical Americas, with a range extending from Argentina to southern Brazil. Garden petunias are among the most popular ornamental plants worldwide and are grown as annuals in temperate regions, while in warmer climates some species are perennial.

Description and growth habit: Petunias are herbaceous, often bushy or trailing plants with simple, sticky leaves and slender stems. The flowers are funnel-shaped with five fused petals, forming a large corolla that comes in a wide range of colors, including white, pink, purple, red, and yellow, often with contrasting centers. Some species and cultivars emit fragrance, particularly at night in certain white-flowered forms. Growth habits vary from compact, upright varieties to cascading, hanging types used in containers and window boxes.

Taxonomy and cultivars: The familiar garden petunias today are primarily hybrids known as Petunia × hybrida, developed from several Petunia species. These hybrids are valued for continuous bloom from spring to autumn in suitable climates. Many modern cultivars are sterile or produce few viable seeds, making cuttings a common propagation method, though seeds are also grown by gardeners.

Cultivation and care: Petunias prefer well-drained soil and full sun, though they tolerate light shade. They require regular watering and benefit from deadheading to promote ongoing flowering. They are generally tolerant of heat but susceptible to frost and cold injury. Common pests include aphids, caterpillars, and slugs, while diseases such as powdery mildew and botrytis can occur in humid conditions.

Uses and ecology: Petunias are frequently used in bedding schemes, borders, and containers, providing long-lasting color and attracting pollinators such as bees. Some fragrant night-blooming forms are particularly prized for evening gardens.