Each class of roses includes plants with different growth traits.
Ground cover roses are low growing plants with canes that trail over the ground, covering their garden space. Depending on the variety, ground cover roses may bloom once in the spring or repeatedly throughout the growing season, presenting either a single flower at the tip of each cane or several flowers "branching" out from the cane. One popular example of a ground cover rose is the moss rose.
Shrub roses differ from ground cover roses in that they grow distinctly upright. They differ from bush roses in that the long canes of shrub roses arch gracefully over your landscape. The heights of shrub roses may vary from four feet tall to twelve feet. Thick foliage and an abundance of canes make shrub roses an excellent choice for a hedgerow, for flower garden backgrounds, and for mass plantings. Like ground cover roses, shrub rose canes may bear either flowers just at their tips or flowers may bud from the sides of the canes. Another distinctive trait of the shrub rose is that, after flowering, many varieties produce red, orange, or yellow rose hips.
Bush roses are, well… bushes. Bush roses usually grow upright and bear flowers on the outsides of the plant. An advantage to growing bush roses is that, because they are compact in nature, bush roses don't need extra supports. Bush rose span a size range from six inches to six feet tall, depending on your climate and the variety of bush rose you choose. The most popular bush roses include hybrid tea roses, floribundas and grandifloras but additionally you'll find bush roses in polyanthus, miniature rose, and heritage rose types.
Just about any rose type can be a tree rose. A tree rose is simply a rose bud grafted onto a straight, healthy trunk. Tree rose trunks usually reach a height of one to two feet, but tree roses of hybrid teas may reach as high as four feet tall. When grafted onto tall trunks, climbing roses present an eye-catching display with an unusual "weeping rose" effect. The tender tree rose is best grown in mild climates.
Most Modern climbing roses are robust plants that repeat bloom throughout the growing season and reach proportions of ten to twelve feet high and/or wide. However, except for those grafted onto trunks and grown at tree roses, climbers need the support of a trellis or an arbor to protect their long canes from damage.
Climbing roses are sub-divided into two types: ramblers and large-flowered climbers. Of the two types of climbing roses, rambling roses have longer, thinner canes and bloom just once a year in late spring or early summer, flowering in clusters of small blossoms. Large-flowered climbers are slower growing than ramblers with thick, rigid canes that reach lengths of up to 10 feet and bloom several times during a growing season.