Adding color to beds and borders, Oenothera are easy-to-grow annual or perennial wildflowers. Sundrops (Oenothera fruticosa) bloom in daylight, while the flowers of Evening Primroses (Oenothera speciosa) open at dusk. Rising above basal rosettes of narrow leaves in late spring and midsummer, the delicate, saucer-shaped flowers glow in the summer garden in cheery yellow, pink or white. Great elements for summer borders or wildflower gardens where they nourish butterflies and bees. After they have faded, many mark their passing with a burst of richly colored fall leaves.