Missouri primrose (Oenothera macrocarpa), also known as glade lily, grows on bluffs and rocky prairies as well as in middle and high desert areas. The native flower grows in the wild in Texas, Missouri and Nebraska. The flowers open in the late afternoon so moths can pollinate the flowers. Then the blooms close forever unless the next morning remains cloudy. Missouri primrose works well in rock gardens, retaining walls or as single mounding specimens where it adds bright color to the area.
A member of the evening primrose family, the native, perennial Missouri primrose grows in clumps up to 12 inches tall and spreads up to 3 feet wide from a single large tuber. The plant sports narrow, glossy green leaves with showy 4-inch, bright yellow blooms appearing in the spring and summer. Irregularly shaped seed pods form after the flowers fade, helping to propagate the plant into new areas when the seeds get dispersed by the wind. Other names for the plant include bigfruit evening primrose and fluttermill.
The large, four-petaled, mildly fragrant blooms last one day, opening in later afternoon and staying open all night before closing in the morning and fading away. Sometimes the faded blossoms appear reddish-orange in color. The plant produces lots of blooms over a period of several months, offering plenty of opportunities to enjoy the brightly colored flowers.
The drought-tolerant plant grows best from seeds planted in full sun in the spring or fall. The plant prefers well-drained, very loose soil, such as sand, rock or gravel. To bloom, the plant must form a large, fleshy tuber-like root, so loose soil helps it develop faster. Missouri primrose thrives in USDA hardiness zones 4 to 9. The plants bloom the second spring after planting. Water the plant regularly until it gets established.
To keep the plant flowering as long as possible, remove faded blossoms after they close the next morning. Avoid completely drying out the soil around the plant. One way to help the plant retain moisture includes adding a layer of mulch around the plant. In the spring, fertilize Missouri primrose with rose food.
The sphinx moth relies on the Missouri primrose as an important food source. The moth, in turn, pollinates the flowers on the one night they bloom. The flowers also attract hummingbirds who use the early morning or late afternoon blossoms as a source of nectar. Butterflies and bees also flock to the blooms. The plant does not appeal to deer.