While the thought of a garden full of flowers that bloom only for one day is daunting, some very popular plants have flowers that do just that. The secret to their popularity is that each of them produces flowers in enough abundance to supply weeks of garden color. Several are available as hybrids, offering a wide ranger of flower colors, sizes and forms. Many are adaptable to growing conditions in both hot and cold climates.
Tropical hibiscus (Hibiscus rosa-sinensis) is one of about 200 hibiscus varieties. A popular warm-weather garden shrub known for its glossy, green leaves and large, showy trumpet-shaped blooms, it normally grows 5 to 6 feet tall. Use it as an in-ground shrub or container plant. Tropical hibiscus is hardy in USDA Plant Hardiness Zones 9 and 10, with minimum winter temperatures between 20 and 30 degrees Fahrenheit.
Tropical hibiscus cultivars bloom in a range of colors including white and several shades of yellow, pink, orange, red, blue and purple. Several of them have bi-color blooms. Attractive to hummingbirds, the flowers may have single or double petals with smooth or ruffled edges. Plants grown in full sun have the greatest number of 24-hour blooms. Tropical hibiscus likes mildly acidic (pH below 7.0), well-drained soil.
Easy-care perennials, daylilies (Hermocallis) are hardy to -40 degrees F. Standing up to 30 inches tall and wide, daylilies are reliable midsummer bloomers available in a large range of combined colors and forms. They grow in clumps with pointed strap-like leaves. Even when they aren't blooming, their bright green foliage adds garden interest.
During July and August, says the Missouri Botanical Garden, daylily's stems bear several 5-inch blossoms that each open for a single day. Planting them in groups ensures a continual colorful display. Many hybrids rebloom after a rest. Plant in full sun to partial shade and well-drained soil. They thrive even in infertile soil and hot, humid summers. Relatively disease- and-pest-free, they spread quickly. Divide large clumps when flower production diminishes.
Standing up to 3 feet high, Virginia spiderwort (Tradescantia virginiana) grows wild from Maine south to Alabama and as far west as Missouri. A meadow and woods perennial, it has branching stalks with arching, vivid green leaves. Between March and August, each stalk produces a cluster of two to three blue-purple, yellow-stamened blooms. Opening in the morning, they wilt quickly and are gone within a day. Plant Virginia spiderwort in rich soil--it's not fussy about soil type or moisture--and sun to part shade. Its tolerance of juglone, a chemical released by black walnut trees that often prevent other plants from growing nearby--makes it a good choice for planting beneath those trees.