Before planting the showy four-o'clock, here are some facts to keep in mind. It thrives in full sun and dry soil that drains well. Once established, the native four-o'clock becomes a large, shrub-like plant 18 to 36 inches tall and 36 to 60 inches wide. It can quickly overwhelm smaller plants that have been planted nearby.
The four-o'clock's mass of foliage will die back to the ground in the fall. It reappears late the following spring only after the soil temperature warms. It is a long-lived perennial that blooms from July to September. The four-o'clock has handsome gray-green foliage and showy, rose-pink flowers that are trumpet-shaped and open in late afternoon and evening.
For more information, see the following Colorado State University Extension fact sheet(s).
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Updated Tuesday, November 19, 2013