Flowering plants come in two categories: those that flower on new wood and those that flower on old wood. Not knowing when plants flower could result in a mistake of pruning at the wrong time. Plants that flower on current-season growth should be pruned in the fall, after they've flowered, or in the spring, before they produce new growth. Pruning any other time greatly reduces the amount of flowers you will see that season.
Clematis is divided into three groups: early flowering, late flowering and large flowering hybrid. Late flowering clematis blooms on current-season growth only. Large flowering hybrid clematis blooms twice in a season, first on old growth and later on new growth. Clematis is a flowering vine that produces colorful summertime blossoms in hues of red, white, blue and purple. This plant varies greatly in size, generally ranging from 6 to 12 feet tall. All forms of clematis require trellising. Though clematis is listed as being hardy in zones 5 to 9 only, the American Clematis Society reports success in growing clematis in zones 4, 10 and 11, too.
Two types of hydrangeas bloom on current-season growth: Hydrangea arborescens and Hydrangea paniculata. Hydrangeas arborescens produces large white flower clusters (capable of reaching 10 inches wide). These plants are reliable bloomers. Hydrangea paniculata is a large shrub hydrangea (averaging 8 to 10 feet tall) that does well in full sun and can be pruned to a tree form. These hydrangea flower clusters are conical rather than round. As the summer lengthens, the white blooms take on a pink hue. The United States Department of Agriculture notes that Hydrangea arborescens grows in hardiness zones 4 to 9 and Hydrangea paniculata in zones 4 to 7.
Many types of roses flower on new-season growth, including tea roses, hybrid tea roses and ever-blooming roses, which include floribunda and miniature roses). Shrub roses and climbing roses flower on old growth. Current-season flowering rose bushes can grow up to 6 feet tall, and all of them bloom during the summer months. Roses are available in every hue except blue or black, and many have a sweet fragrance. Texas A&M notes that hybrid tea roses (a current-season bloomer) are the most widely grown roses in the United States. Rose bushes grow primarily in hardiness zones 4 to 8, with some varieties displaying greater cold hardiness than others.