Annual flowers are defined as those with one growing season; however, some have an additional season with the best conditions. Annuals for yard plants can be ones that provide interesting foliage, bright flowers or "filler" needed between other plants while they are growing into their gardening spots.
Senecio cineraria from the aster/daisy family, better known as dusty miller, is a woolly annual with silvery gray leave. This much-used foliage plant adds character to a garden plot. The plant gets 2 feet tall with 1-inch wide yellow flowers in the second season of growth (although second growth seasons occur only rarely). Grow this plant in full sun in well-drained soils. Propagate via cuttings or seed in USDA hardiness zones 8 through 10.
Atriplex hortensis from the goosefoot family, also known as orach or mountain spinach, is a vegetable garden plant that can be used anywhere. It grows between 2 and 6 feet tall, depending on cultivator, with leaves that are red, purple, green or yellow-green. Grow this plant in poor soil in full sun. Propagate it via seed in USDA hardiness zones of 8b through 11.
The California poppy, or Eschscholzia californica, is an easy-to-grow annual. It will get 12 inches tall with fernlike gray-green leaves 6 to 8 inches long with 2- to 3-inch wide flowers. The California poppy typically produces blooms in red, yellow or orange. Propagate via seed in USDA hardiness zones of 5 through 10. Plant the poppy in full sun in well-drained poor soils.
One fast-growing annual that's easy to grow is Helianthus annuus from the aster/daisy family, better known as the common sunflower or mirasol. Although this annual comes in many sizes and colors because of cultivators, most sunflowers grow 8 to 15 feet tall. Ray flowers are yellow with rough and hairy leaves. Grow this plant in well-drained soil in nonacidic soil in full sun. Seed is the best way to propagate this plant.
Rudbeckia hirta from the aster/daisy family, also known as black-eyed susan or gloriosa daisy, is mostly an annual. Stems get 3 feet tall with 2- to 3-inch hairy leaves and flowers of different sizes in yellow or gold. This annual grows best in full sun or light shade with regular watering. Propagate via seed or division in USDA hardiness zones of 3 through 10.