Meet the rebel of the Evening Primrose family. These unique bloomers generally open at dusk (hence the name) putting on a pretty show of pale, yellow flowers at night, into early morning.
Pink Evening Primrose, or Pink Ladies as they are sometimes called, are different from traditional primroses. They flower pink, instead of yellow, and flower all day long, loving heat, drought and the worst conditions imaginable.
In dry, infertile planting sites, this long-blooming perennial is fairly well-behaved. Masses of shell-pink flowers cover a mounding, bushy plant from June to September. It's what's called a 're-seeding annual.' Meaning it's not an annual at all. It's basically a headstrong beauty with a real mind of her own. Pink Ladies will show up in a new location in your garden every year.
Do well by this flower and suffer the consequences. In moist, fertile soil it will take over your garden in one short year. That's why this particular variety is banned from sale in many states. Tame this problem child by placing it in the most inhospitable area you can find.
* Oenothera speciosa, Pink Evening Primrose, USDA Zones 5-9, is available from High Country Gardens and other wildflower specialty stores.