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Plant library  ·  Annual Flowers

Four O'Clock

Mirabilis jalapa

Four O'Clock forms a bushy, roughly 3-foot-tall plant with fragrant trumpet flowers that open late in the afternoon. Its early-summer-to-fall display gives a bed a later-day focal point rather than an all-day flower show. Use it where its evening fragrance can be noticed and where the plant’s 2½-foot spread can read as a rounded midsize mass.

Sunlight Full Sun
Water Moderate
Planning spacing 2 ft
Typical mature size 3 ft tall, 2.5 ft wide
Typical bloom Early summer - fall

Four O'Clock spacing and mature footprint

Space Four O'Clock 2 ft apart, measured center to center (60 cm).

The mature spread is about 2.5 ft (75 cm), so plants set at that distance grow together into a closed canopy over the bed.

Treat 2 ft as a planning baseline — cultivar and local growing conditions shift the final footprint.

Compare with the full annual flower spacing chart

Three plants set 2 ft apart, center to center; shaded circles show the 2.5 ft mature spread.

Placement and use

Place Four O'Clock toward the middle or back of a sunny annual border, behind lower edging plants and clear of narrow circulation routes. A position beside a patio, pool, sitting area, or evening path makes the late-opening, fragrant flowers part of how the space is used after the heat of the day. Group several plants in a loose drift rather than making a tight front-of-bed line; the bushy form needs room to hold its outline.[1][2]

Spacing and mature footprint

Set plants 2 feet apart, center to center. Each plant can finish about 2½ feet wide, so neighboring plants may knit into a broad, informal planting mass as the season advances. Keep the first row at least 18 inches back from a path or bed edge to prevent the foliage from leaning into walking space and to leave a practical reach-in zone for cleanup.

Sun, water, and soil

Use a full-sun position for the fullest growth and flowering. Give plants moderate water, especially while they are establishing, without turning the planting area into a persistently saturated pocket. A well-drained bed is a sound fit, so avoid placing it at the bottom of a slope or beside downspouts where water collects after rain.[1][2]

Seasonal notes

Flowers begin in early summer and continue into fall, opening in late afternoon or early evening and fading by the following morning. Plan the surrounding bed for its evening presence: leave sightlines from a porch or seating area, and avoid burying it behind taller late-season growers. The plant is annual in this planting plan, so the space becomes available again after the season ends.

Planning caveats

Allow a little buffer around Four O'Clock in beds where volunteer seedlings would complicate the next year’s layout. It can self-sow vigorously, particularly in warm conditions, so remove unwanted seedlings early and keep it out of tightly choreographed planting patterns unless reseeding is welcome.[1]

Growing facts

Botanical name
Mirabilis jalapa
Type
Annual
Category
Annual Flowers
Lifecycle
annual
Sunlight
Full Sun
Water
Moderate
Planning spacing
2 ft
Typical mature size
3 ft tall, 2.5 ft wide
Typical bloom season
Early summer - fall
Plan a garden with four o'clock

References

  1. Mirabilis jalapa (Four-o'clock, Marvel-of-Peru) — North Carolina Extension Gardener Plant Toolbox
  2. Four O’Clocks — Gardening Solutions, University of Florida IFAS