Four o'clock

The Four o'clock, scientifically named Mirabilis jalapa and known as the Marvel of Peru or Beauty of the Night, is a highly popular, bushy perennial belonging to the Nyctaginaceae (four o'clock) family. Native to the tropical regions of South America, particularly the Andes of Peru, it was introduced to Europe in the 16th century and has since naturalized in warm-temperate and subtropical zones worldwide. This plant is famous for its bushy, shrub-like growth habit and its unique nocturnal blooming schedule, making it a staple of twilight and evening sensory gardens.

Growing as a tender perennial, it forms a lush, rounded mound that stands 2 to 4 feet tall and wide, supported by thick, branching stems and large, tuberous roots. The plant features smooth, deep green, ovate leaves that grow in opposite pairs along the stems. Its trumpet-shaped flowers are about 2 inches long with a 5-lobed flared opening. Remarkably, these blooms contain no true petals; the colorful trumpet is actually a modified, petaloid calyx (sepals). The flowers come in a spectacular spectrum of magenta, red, yellow, white, and orange, often with multiple distinct colors or striped, bicolored patterns appearing simultaneously on a single plant.

The architectural structure of the flower is represented by the floral formula EBr ⊕ ☿ P(5) A5 G(1). This formula shows that the bloom is ebracteate (lacking true bracts, though surrounded by a sepal-like involucre), actinomorphic (radially symmetrical), and bisexual. It features a perianth (P) of 5 fused petaloid sepals forming the trumpet tube, 5 free stamens of unequal lengths that emerge from the tube, and a unicarpellate gynoecium with a single superior ovary containing a single ovule.

Mirabilis jalapa is exceptionally easy to grow and thrives in USDA hardiness zones 9 through 11 as a perennial, while being treated as a fast-growing annual in colder zones (zones 3 to 8). It prefers full sun to partial shade and is highly tolerant of urban heat, humidity, and drought once established, though it performs best in rich, well-draining loamy soils with regular moisture. Its key behavioral characteristic is that its blooms open in the late afternoon (around 4 PM) and remain open through the night, releasing a sweet, citrusy fragrance before closing forever the next morning.

The genus name 'Mirabilis' is Latin for 'wonderful' or 'marvelous,' celebrating the plant's stunning variety of colors, while 'jalapa' refers to the city of Xalapa in Mexico. In regional languages, it is known as गुल अब्बास (Gulabbas) or संध्या मालती (Sandhya Malti) in Hindi, and Chandrakanta in Telugu. Historically, the Aztecs cultivated this plant for both its aesthetic charm and its medicinal properties. Today, it stands as a symbol of mystery, quiet grace, and nocturnal beauty.

Pet owners must exercise significant caution with this species. Mirabilis jalapa is TOXIC to dogs, cats, and horses. The seeds and the dark, tuberous roots contain toxic resins, glycoproteins, and the alkaloid mirabilisine, which cause moderate to severe gastrointestinal distress, including vomiting, diarrhea, abdominal pain, and lethargy if ingested. The sap can also cause mild skin irritation upon contact. It is highly recommended to plant them in elevated containers or fenced garden areas out of pets' reach. For first-aid steps and alternative pet-safe options, consult our Pet Guard guide.

Four o'clocks are sometimes confused with Petunias due to their trumpet shape and bushy growth. However, they are easily distinguished by their evening-only blooming habit, their larger, smooth, non-sticky leaves (petunia foliage is hairy and sticky), and their unique, hard, wrinkled black seeds that resemble tiny hand grenades. They make excellent companion plants for night-blooming gardens; we suggest pairing them with Parijat or Tuberose. Explore more in our Flower Identifier.