The name of this lovely flower offers a hint to its special daily performance -- the trumpet-shaped blooms of this shrubby perennial open in mid-afternoon and stays open all night. It's not an early happy hour that causes the flowers to open, it's the drop in temperature in the late afternoon. The flowers stay open until the sun warms the air the next morning.
Gardeners suggest planting them close to a patio or deck, where you can enjoy their strong fragrance in the evening. Flowers in bold colors of fuchsia, yellow or white add dramatic color to your garden; they'll start to bloom in midsummer and will flower until frost. Four o'clocks grow in both full sun and partial shade, need very little water, and will grow to be 3 to 4 feet (0.9 to 1.2 meters) tall [source: Thigpen].