Low-maintenance plants have certain characteristics, according to floriculturist Sharon Bale of University of Kentucky Extension. They must be adapted to hot, dry conditions and be relatively pest and disease resistant. Flowers should bloom uniformly and consistently throughout the summer until frost, and require no maintenance or deadheading. They must be available in broad ranges of colors and sizes and grow uniformly from seeds or cuttings. There are a number of annual flowers that fit the description.
Catharanthus roseus, or annual vinca, is a cheerful annual that is grown in zones 2 to 11. Similar to impatiens, it produces flowers through the growing season as long as it remains frost-free. Annual vinca, sometimes known as periwinkle, does not require any deadheading. It withstands drought, but does best with adequate water. Use the plants in beds, borders and containers for maintenance-free growing. Plant groupings of eight for showy swathes in areas that receive (at least) a half day of sun. Vinca forms mounds that add texture to other plants, such as angelonia and calibrachoa. It is available with blooms of pink, red, lavender and white.
Begonia semperflorens x cultorum provides gardens with great colors for minimum care. It tolerates sun or shade, moist but well-drained environments and soil that contains organic materials. Similar to vinca, begonia is a tender annual that is self-cleaning and requires little care beyond watering. It is available in red, pink, white and bi-color, and blooms from May to October in most areas. The plant has waxy green foliage that contrasts nicely with the blossoms. Propagate plants through seed, cuttings, division or separation. Use them in shade alongside impatiens for brightening up darker parts of the garden.
Salvia farinacea, or annual salvia, has deep blue blossoms on tall spikes and tolerates heat, humidity and poor soils. It is native to Texas and Mexico, perennial to zone 7 and used as an annual plant in cooler climates. It is a member of the mint family and prefers well-drained soils and full sun. Victoria Blue is the most commonly planted salvia, and it doesn’t require deadheading like its cousin, Salvia splendens. Salvia can be used for cutting and the blossoms are long-lasting. Blue salvia attracts butterflies and hummingbirds to gardens. The flowers can also be dried for winter arrangements.