Master Gardeners gardening and blogging in the mountains of Colorado. For more information contact your local extension office, wwwhttp://extension.colostate.edu/staff-directory.
Friday, May 21, 2021
Another of My Favorite Native Flower Tufted Evening Primrose (Oenothera caespitosa)
By Ed Powers, Jefferson County Master Gardener
The Tufted Evening Primrose caught my attention when I moved into my Evergreen home. My south-facing hillsides have a number of these plants. We tried to repot them and read that Evening Primrose is available as potted plants or seeds from many sources.
They require moderate watering to keep it blooming all summer. Soil should not be heavy and must have good drainage. However our potted plants did not survive. So I decided the best way is to take care of them on the hillsides. Which we do.
I did some research on them and this some of the information I found. I used background information from Garden Notes of Colorado State University.
Tufted evening primrose or Oenothera caespitosa, is known commonly as tufted evening primrose, desert evening primrose, rock-rose evening primrose, or fragrant evening primrose. It is a perennial plant of the genus Oenothera, native to much of western and central North America which includes Colorado.
It is a low-growing stemless perennial with gray-green fuzzy leaves and wonderful 3-4 inch fragrant white flowers that open in the evening and close in the mid-day heat. It grows in sunny, dry, infertile, rocky, well-drained soils. This plant is showy, and requires little water, which makes it a perfect candidate for western xeriscape gardens.
As the name implies, this family has many species that bloom in the evening, the flowers stay open all night, and then wilt the next day. The flowers are usually white or bright yellow and attract large night-flying insects like hawk moths (family Sphingidae).
In the evening-primrose family, the flowers often have a long floral tube that holds the petals well above the base of the flower. Nectar collects in the base of the tube so only long-tongued visitors can get a nectar reward. Again, hawk moths with their long coiled tongues are perfectly adapted to reach the nectar in evening-primrose flowers.