Petunia

Petunia is genus of 20 species of flowering plants of South American origin. The popular flower of the same name derived its epithet from the French, which took the word petun, meaning 'tobacco,' from a Tupi–Guarani language. An annual, most of the varieties seen in gardens are hybrids (Petunia × atkinsiana, also known as Petunia × hybrida). Petunia is a genus in the family Solanaceae, subfamily Petunioideae. Well known members of Solanaceae in other subfamilies include tobacco (subfamily Nicotianoideae), and the cape gooseberry, tomato, potato, deadly nightshade and chili pepper (subfamily Solanoideae). Some botanists place the plants of the genus Calibrachoa in the genus Petunia, but this is not accepted by others. Petchoa is a hybrid genus derived from crossing Calibrachoa and Petunia. Species include: Petunias are generally insect pollinated, with the exception of P. exserta, which is a rare, red-flowered, hummingbird-pollinated species. Most petunias are diploid with 14 chromosomes and are interfertile with other petunia species. The tubular flowers are favoured by some Lepidoptera species, including the Hummingbird hawk moth. The flowers are eaten by the larvae of the corn earworm, Helicoverpa zea and the cabbage looper, Trichoplusia ni. Petunias can tolerate relatively harsh conditions and hot climates, but not frost. They need at least five hours of sunlight every day and flourish in moist soil and conditions of low atmospheric humidity. They are best grown from seed. Watering once a week should be sufficient in most regions. Hanging baskets and other containers need more frequent watering. Maximum growth occurs in late spring. Applying fertilizer monthly or weekly, depending on the variety, will help the plant grow quickly. Petunias can be cultivated in hanging baskets.