Durable and drought-tolerant, four o’clocks are fascinating flowers with time-telling abilities in the garden. A hardy perennial in the Coastal Bend, they bloom from early summer through fall until the first frost or freeze. With an upright growth structure in dense clumps, the trumpet-shaped flowers come in yellow, red, pink or white.
Like clockwork, four o’clocks bloom every afternoon around 4 p.m., and stay open through the evening. For this reason, the flower is a classic feature of the Linnaean Flower Clock.
The four o’clock flower gets its Latin name—Mirabilis jalapa, meaning “wonderful” and “from Mexico”—from the Swedish botanist Carl Linnaeus, whose binomial nomenclature method assigned two Latin names, genus and species, to every plant.
His Linnaean Flower Clock uses a circular design to indicate the time with flowers positioned based on when they bloom. For instance, dandelions open at the 5 a.m. spot, and morning glories bloom in the 7 a.m. spot.
Four o’clocks are unique flowers, distinguished by their remarkably precise blooming time. Their dependability is so exact, you could practically set your watch by them.
Gardener’s Notes
Growing Up: Spacing, 18” to 24”. Height, 24” to 48”. Full sun. Requires rich, well-drained soil. Can be planted by seed or transplanted. Add four inches of organic compost to the soil when planting. Add ½ cup pastured poultry manure and ½ cup wood ash per square foot. Water three times per week for the first two weeks, then twice per week through the summer or as needed. Mulch with native leaf mulch. Durable once established. Reseeds easily; can become a (beautiful) weed.
Profiling: Four o’clocks are resilient once established. They grow into bushy clumps with tall, greenish-brown stems. Well-fertilized and well-watered four o’clocks can become very lush and dense. To harvest cut flowers, clip the stems low at the base near the soil. Harvest up to 1/3 of the clump at a time. Try to take every third stem to increase airflow. Four o’clocks bloom in the afternoon in a vase as well as in the garden.
Fun Facts: To create your own Linnaean Flower Clock garden in the Coastal Bend, try these beautiful and interesting flowers: Morning glory blooms in the early morning hours. Mexican petunias bloom next, followed by scarlet sage. Around noon, lantanas bloom, then hibiscus, then globe amaranth. In the late afternoon, four o’clocks bloom with their gorgeous trumpet-shaped flowers. Evening primrose blooms around dusk. After dark, moonflowers and night phlox bloom to take the garden back to sunrise.
