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How to Grow a Four O'Clock Plant

By Katelyn Lynn ; Updated September 21, 2017

Four o’clocks are indigenous plants to the country of Peru and are also referred to as Mirabilis jalap and marvel of Peru. They are a member of the Nyctaginaceae family. Four o'clocks are regarded as perennial plants in zones 4 through 24, and annuals in zones 1 through 3. Four o’clocks grow as mounded shrublike plants which can achieve heights of 3 to 4 feet. The flowers of the four o’clock are trumpetlike in shape and range in color from various shades of pink, yellow, tricolor and white.

Planting Four O’clock Seeds Indoors

Purchase some four o’clock seeds. Or if you have access to established four o'clock plants, collect seeds after they bloom.

To get an early start in spring germinating your four o'clock seeds indoors, soak the seeds in warm water for 12 hours, or overnight.

Fill each peat pot, or planting cell, full of potting soil mix. Water each, and let all the water drain away.

Push 1 to 2 four o'clock seeds into each planting cell or peat pot. Cover with no more than approximately 1/4 inch of potting mix. Spritz the seeds with your garden sprayer or plant mister.

Place the planting cells or peat pots in a warm (65 to 70 degrees F), light-filled area in your home. Strive to maintain them in an area that will receive approximately 8 hours of light each day, preferably sunlight. Check the seeds every day. Maintain moisture levels by spritzing with water every few days, or if the soil appears overly dry.

Once your four o'clock seeds have sprouted, typically 7 to 10 days, and are about 2 inches in height, choose a location in your garden that is conducive to growing four o'clock (see Tips below for more information).

Dig holes for your four o'clocks which are twice the width and depth of the planting receptacle and are spaced at 15 to 18 inches apart. Fill the holes halfway up with water and let the water drain off. Remove a four o'clock from a planting cell by pushing up from the bottom, being careful with the root. (Peat pots can be planted straight into the ground; they will disintegrate). Gently place a four o'clock seedling into a hole level with the surface of the topsoil. Fill up the entire hole with dirt. Water each seedling carefully, letting the water run slowly at the base of each seedling. For further care and maintenance of your four o'clocks, see Tips below.

Planting Four O'Clock Seeds Outdoors

After you are sure there will be no more frost, choose an area in your garden where you want to plant your four o'clock seeds. (See Tips below for growing conditions information). Rake the area in your garden smooth and level. Dampen the soil, but don't saturate it.

Push 2 to 3 four o'clock seeds into the soil to a depth of 3/8 to 1/2 inch. Cover the seeds up with topsoil. Spacing should be approximately 3 to 4 inches apart in rows 12 to 18 inches apart. Spritz the seeds gently with water. Push planting stakes around the area where you planted your four o'clock seeds so you know where to water.

Check the area you planted your four o'clock seeds daily. Water your four o'clock seeds when the topsoil appears dry using a gentle mist. Germination for outdoor sowing of four o'clocks varies, but you should see sprouts in 7 to 10 days.

Once your four o'clock seedlings have reached approximately 3 inches in height, thin them out to 10 inches apart. (See Tips below for more information on caring for your four o'clocks).


Things You Will Need

  • Four o'clock seeds
  • Potting mix
  • Planting cells or peat pots
  • Trowel or shovel
  • Planting stakes
  • Plant sprayer, or plant mister


  • Four o'clocks thrive in full sun, and although they aren't fussy about soil conditions, they prefer slightly alkaline soil, in the range of 6.1 to 6.5 pH.
  • If you live in zones 7 through 9, Floridata.com recommends mulching your four o'clocks with straw in order to overwinter them in the garden.
  • During the growing season, water your four o'clocks regularly.

About the Author


Katelyn Lynn has been writing health and wellness articles since 2007. Her work appears on various websites. Lynn is a certified holistic health practitioner who specializes in orthomolecular medicine and preventative modalities. She is pursuing a Bachelor of Science in health sciences from TUI University and has extensive experience in botany and horticulture.