Four o'clock plants (Mirabilis jalapa) are bushy blooming perennials. These tuberous-rooted plants produce slightly pointed oval leaves on branching stems. They get their common name because of the way they bloom. The flowers open in the late afternoon, typically around 4 p.m. or so, and then remain open until the next morning. The approximately 2-inch-long blooms are trumpet-shaped with five petals, and they come in several colors, often shades of pink and red. Some four o’clock plants produce flowers in multiple colors, sometimes with marbling or other markings. This is a fast-growing plant that often sprawls in the garden. It’s best planted in the spring.
It's important to note that all parts of four o'clock plants are toxic both to people1 and pets.2
Common Name Four o'clock plant, marvel of Peru, garden jalap
Botanical Name Mirabilis jalapa (synonym: Mirabilis lindheimeri)
Family Nyctaginaceae
Plant Type Herbaceous, perennial
Mature Size 2–3 ft. tall and wide
Sun Exposure Full, partial
Soil Type Moist, well-drained
Soil pH Acidic, neutral
Bloom Time Summer, fall
Flower Color Pink, red, yellow, white
Hardiness Zones 9–11, USA
Native Area South America
Toxicity Toxic to people, toxic to pets
Four O'Clock Plant Care
Because four o'clock plants bloom in the late afternoon and evening, it's best to plant them where you’re sure to see them and catch a whiff of their fragrance, such as around a patio. They grow well in garden beds or in container plantings, and they mingle and grow through other plants nicely, making a pretty underplanting.
Four o’clock plant maintenance is fairly simple. Expect to water your plants fairly regularly if you don’t have rainfall, and feed them throughout the growing season. They’ll also need a bit of pruning to keep them looking fresh and healthy.
Four o' clock flowers
The Spruce / Autumn Wood
Light
Four o'clocks thrive in full sun, meaning approximately six hours of direct sunlight on most days. They will tolerate partial shade, though the plants might become somewhat leggy and not bloom as profusely in locations that are too shady.
Soil
These plants can grow in a variety of soil types. But rich, loamy, well-drained soil is ideal. And a neutral to slightly acidic soil pH is best.
Water
Do not let these plants dry out; water whenever the top 1 to 2 inches of soil becomes dry. But avoid overwatering, as soggy soil can cause root rot. Mulching around the plants can help to keep the soil sufficiently moist. Plants grown in containers will generally need more regular watering than those in the ground.
Temperature and Humidity
Four o’clock plants thrive in warm temperatures and are often grown as annuals in cooler climates outside of their growing zones, where the plants die once frost and cold fall temperatures arrive. Humidity typically isn’t an issue for them as long as adequate soil moisture is maintained.
Fertilizer
Apply a balanced fertilizer in the spring, and continue to feed monthly until fall. However, if you already have rich soil, you might only need to give your plants the one spring feeding.
