Managing Giant Four O'Clocks: Support, Division, and Seed Saving

A massive Mirabilis jalapa (four o'clock) with flopping stems signals abundant growth—not necessarily a problem.

Immediate Actions

• Stake or cage now—don't dig/divide in active growth.
• Water deeply weekly if dry.
• Some seed pod abortion is normal.

Division (If Needed)

• Best done dormant (late fall or early spring).
• Tuber resembles carrot with "eyes" like potato.
• Cut into sections with at least one eye each.
• Dust cuts with fungicide; store cool/dry in peat.

Seed Saving (Easier)

• Collect black seeds when pods dry.
• Sow directly ½" deep after frost.
• Germinate in 7–10 days at 75°F.
• No stratification needed.

Hardiness Notes

• Zones 7–9: Tuber overwinters in ground.
• Zones 5–6: Self-seeding annual.
• Zones 10–11: Perennial shrub.

Enjoy the fragrant evening blooms; this tough plant asks little and gives much.