|O. albicaulis a spreading annual usually known as a biennial, sometimes short-lived perennial, blooms in a single bowl-shaped primrose that opens white, then turns cream and pale pink in the morning. Plant in spring among other full sun plants. You should divide the clumps every 3 years to encourage them to flower. Evening Primroses are excellent perennials for weekend gardeners, since they are simple to grow, with almost no pests or problems.