Mirabilis Jalapa, also called four o'clock and marvel-of-Peru, is a very easy plant to grow as an addition to any garden or landscape. The perennial grows 2 to 3 feet tall and wide and has 2- to 4-inch blooms. Native to the tropical regions of South America, the Mirabilis Jalapa has become a naturalised plant in the southern United States. Mirabilis Jalapa is fast-growing and trouble-free, requiring little maintenance and thriving in almost any type of soil. Hardy in USDA zones 7 to 11, the perennial is not tolerant of frost, and the seed will not survive winters that get below --15 degrees C.
Choose an area with full sun or partial shade.
Loosen the soil where you want to plant the seeds with a cultivator. Loosen the soil down 2 or 3 inches, so the roots can easily spread into the soil.
Spread the soil back into place, but leave ½ inch of soil off of the planting bed.
Spread the seeds on the newly loosened soil, spacing them 1 to 2 feet apart.
Cover the seed bed with ½ inch of soil. In 7 to 14 days, the seeds will germinate.
Water the seeds gently.
Once per month, add a mild liquid fertiliser to the plants. In colder climates, you can save the seeds each year and replant Mirabilis Jalapa each spring. The plant grows fast enough to bloom and reseed each year. Detach the dead flower before it seeds to prevent additional plants from growing the next year.
The seed and plant are poisonous if ingested. Mirabilis Jalapa can become invasive if the seeds are not retrieved each year after they fall.