The United States Department of Agriculture lists 10 growing zones according to their average winter minimum temperature. The USDA plant hardiness map lists zone 6 winter temperatures as -10 to 0 degrees F. Zone 6 stretches from areas of Arizona through the mid-west to Maine. The below-freezing winter weather conditions of this zone create specific needs for plants and trees. Many plants and flowers grow well in zone 6.
Annuals are plants which grow, bloom and die in one growing season. Annuals that do well when grown in planting zone 6 include ageratum, calendula, cosmos, dahlia, dianthus, petunias, fuchsia, lobelia and zinnia. Salvia and verbena grow in a wide range of colors from dark purple to red, pink and light blue. Verbenas grow well as hanging basket flowers in zone 6.
The perennial sunflower variety Low Down Dwarf is hardy in zone 6. Other perennials capable of over-wintering in low temperatures are coreopsis, yarrow, Tomato Soup coneflower, campanula, delphinium, dianthus, geranium and hellebores. Vinca and viola both have small purple or blue flowers and are often used for flower border edgings. Japanese primrose bloom clusters of small pink flowers on 10-inch stems and are used as border plants or cut flowers. They also do well in the shade.
Tulips grow well in cold winters and provide a spectacular carpet of blooms in the springtime. Other bulbs that thrive in zone 6 are all the varieties of iris, tuberous begonia, narcissus, hyacinth, gladiola, crocus, cannas and caladium. Caladium does well as a mass planting in a shaded area. Crocuses are frequently the first bulb to bloom after winter.
Azaleas are popular in all areas of zone 6 because the cold winters help them produce strong growth and flowers in spring. Popular varieties of azalea include Appalachian Trail, White Lightning and Flame. American Beautyberry has large clusters of bright lavender berries and grows well when naturalized in a wooded area. Lilacs, hummingbird plants and hydrangea, along with crepe myrtle, are also popular shrubs for zone 6.
Flowering vines grown in zone 6 include the popular trumpet vine, which can reach a height and length up to 30 feet. Trumpet vine flowers are 2 ½ inches long and bloom in colors from orange to shades of red. Honeysuckle has yellow, fragrant blooms and attractive green-purple foliage. Jasmine is a very adaptable vine for zone 6 growing. It provides large masses of very fragrant flowers from February through March.