After the sun sets, these flowers spring open in seconds. The trick is being there when it happens, since they take their time getting ready. The flowers in the video were shot at normal speed, no time lapse, no acceleration. The entire sequence was over a a bit under 30 minutes, starting just after sunset. The intervals between openings were edited a bit – and we noticed that each stem has its own rhythm.
Hooker’s evening primrose (Oenothera elata) is native to California, where it grows in meadows with some moisture. It likes disturbed areas where it can reseed, since plants only live a maximum of two years, so part of keeping them around is making sure they have their own place. This said, they reseed vigorously where conditions are right, so be prepared to pull out unwanted seedlings as needed.
In the wild, they typically grow in riparian areas, not in water but not far from it – although as long as they have wet growing conditions in spring during California’s normal rainy season they seem to tolerate drier conditions through summer, although you may not get as many flowers.
The plants are easy to grow in full sun. Plant them in a back corner where you can watch the flowers open in the evening and appreciate them in the morning, but don’t make them a centerpiece since as the sun rises the flowers wilt, leaving tall green stalks. This year’s plants are over six feet (two meters) tall, growing with ornamental grasses and asters.
This is a decent wildlife plant. The seeds feed goldfinches in the fall. Sphinx moths may visit the plants by night, and hummingbirds may stop by early in the morning before the flowers fade. We’ve also seen carpenter bees in the flowers.
The plant may be a caterpillar host for white-lined sphinx moths, although I’ve never seen any larvae on the plants. This is a very decorative moth, sometimes confused with hummingbirds because they hover in front of flowers.