The Top Performing Annual Flowers

Hardy Annuals

• Hardy annual flowers are cold-tolerant and can withstand light frost and even a short freeze without harm. These flowers are ideal for fall and spring planting but will not withstand the heat of summer. In milder climates, hardy annuals will thrive all winter. The pansy (Viola wittrockiana) is a happy plant that adds charm and color to the garden. Grown in winter gardens in the South and Southwest, the pansy has edible, brightly colored flowers. Use for edging or in pots for best results.

  Another reliable annual that performs well in cool temperatures is sweet alyssum (Lobularia maritima), which displays dense clusters of white flowers in cool temperatures. This dainty but hardy annual grows rapidly and emits a pleasant fragrance.

Half-Hardy Annuals

• Half-hardy annuals can tolerate some periods of cool and wet weather but will not stand up to a frost. Seeds can be planted after the last spring frost, before the ground temperature has warmed. Don't give up on half-hardy annuals if they start to look a little ragged come summer. Leave them in the ground and they often perk up with cooler weather in the fall. The strawflower (Bractheantha bracteata) has a unusual straw-like texture, making it an excellent dried flower for crafts or arrangements. Growing only to 14 inches, this half-hardy annual blooms in pink, yellow, white and red.

  Sow baby's breath (Gypsophila paniculata) in spring for an extraordinary display of tiny white flowers and fluffy foliage. This half-hardy annual is a welcome addition to any window box or hilly rock garden.

Cool Season Annuals

• Cool season annuals are not fond of daytime temperatures over the mid-70 degree range. These plants perform well in early spring and fall but do not tolerate the heat of the summer well. The petunia (Petunia x hybrida) is a popular annual flower with reliable performance during cooler seasons. This prolific, low-bloomer does best in full sun or partial shade. Petunias are available in a rainbow of colors. Growing habits vary from clumping to trailing, making them ideal of containers or edging.

  The snapdragon (Antirrhinum majus) is another flower that likes mild temperatures. Plant snapdragons from plants for best results, as the tiny seeds can take almost three weeks to germinate. Snapdragons like full sun and can withstand a frost. This highly fragrant flower is available in a rainbow of colors and will bloom into early summer and again in the fall.

Tender Annuals

• Tender annuals do not like cool soil or frost, so wait until three weeks after the last spring frost to sow seed. If the soil is too cold, the seeds will rot before they get a chance to germinate. Most tender annuals are native to tropical areas. The morning glory, in the family of Convolvulaceae, is one of the best flowers to decorate fences, walls and trellises. This vining annual opens up in the morning and takes a nap in the afternoon. This rapidly growing plant produces bright, trumpet-shaped flowers and heart-shaped leaves.

  Another garden favorite is the zinnia (Zinnia elegans), a member of the aster family. Butterflies and hummingbirds love the bright flowers and sweet nectar. This plant is easy to start from seed and will bloom profusely into the fall. Colors are bold and habits range from dwarf to tall, making this an ideal border or back of the bed plant.

Warm-Season Annuals

• Warm season annuals thrive in daytime temperatures over 80 degrees and nighttime temperatures in the high 60s. Do not plant these heat-loving plants until the late spring or early summer for best results. Four o'clocks (Mirabilis jalapa) are easy to start from seed and thrive in warm temperatures. These old-fashioned favorites open late in the day. Plant from seed after threat of frost for profuse blooms all summer long. Four o'clocks do well in poor soil and can withstand drought conditions.

  Blue daze (Evolvulus glomeratus) is a trailing plant native to Brazil and Paraguay. Because it is low-growing, this warm-season annual is ideal for garden borders or hanging baskets. With its olive-colored foliage and light blue flowers, blue daze deserves a front row spot in any garden.