The common name of four o'clocks was given to Mirabilis jalapa because the flowers of this plant do not open until late in the day. This old-fashioned garden ornamental in the four-o'clock family (Nyctaginaceae) is a tender perennial hardy in Zones 7-11. Four O'Clock mix has trumpet-shaped flowers that open in the evening. The sweetly fragrant flowers attract hummingbirds. Four o'clock isfrom tropical South America, and introduced in North America, mainly in southern, eastern and western states. It is a popular garden ornamental in southern climate zones, where it grows rapidly. Care It grows in full to part sun, with moderate to moist conditions in rich and well-drained. It is drought tolerant. Growth Habit Four O'Clock – blossoms from white to yellow, orange, pink or red; the old fashioned look. This heirloom tuberous perennial quickly develops into a bushy plant that is covered with fragrant, trumpet-like blossoms; carrot shaped top sized. Toxicity Every part of the Four O'Clock plant is toxic to dogs, but the roots and seeds contain the highest concentration of harmful alkaloids. The seeds, in particular, pose a risk if chewed or swallowed, potentially causing gastrointestinal upset. Skin contact with crushed seeds or roots can also lead to irritation.