Annual flowers are short-lived plants that only live for a year before dying back down to the ground. Flowering annual plants are frequently used for colorful flower beds that peak in spring and summer, or for window boxes and containers. Many annual flowers are frost sensitive, but will handle partial or full shade.
A member of the violet family, the pansy (Viola x Wittrockiana) is a garden hybrid perennial most commonly grown as an annual. The low-growing plant, which is usually between 4 to 10 inches tall, is notable for its tolerance of shade and for its broad, multi-colored flowers. Pansies grow well in partial shade in USDA zones 7 to 10, though they may be grown in deep shade too. The hardy, pest-free flowers aren't picky about growing conditions and will tolerate most types of soil, as well as containers. If you plant to grow pansies in a light, sandy soil, be sure to mix in some organic matter. Water the pansies when the soil is dry, and pinch back dead flowers.
Wishbone flower (Torenia fournieri) is a low-growing annual that rarely grows above a foot high. The plant boasts broad, heart-shaped leaves and flowers that range in color from pink to white or purple, though they are mostly commonly seen in blue. The plant is a popular choice for annual flower beds or borders, and does well both indoors and outdoors in a container. Wishbone flower will only really thrive in shady situations, and the plant may be grown in the spring in most gardening zones. Wishbone flower prefers a soil that is rich and consistently moist. As a general rule, wishbone flower is a healthy plant with few disease problems.
Impatiens (Impatiens wallerana) is a summer blooming annual that can be grown throughout the United States in USDA zones 4 to 10. The plant ranges in height from about 1 to 2 feet, producing bushy leaves and silky flowers in a tremendous range of colors. The plant has a mounding habit, making it especially popular as a border plant or as a compact hanging basket plant. Impatiens does best in partial shade, or even almost complete shade in hot climates. Grow impatiens in a fertile, well-draining soil and water when dry. Fertilize the plant throughout the growing season to keep the flowers blooming.