The easiest way to classify roses is to group them into seven basic categories: hybrid teas, floribundas, grandifloras, miniature roses, climbers, old-fashioned roses and shrub roses. Here’s a very general description of these categories:
Hybrid Teas are the sophisticated roses with one large flower per stem. They have thick petals, long stems and make excellent cut flowers. These are the roses you find in florist’s shops. They tend to be medium-sized shrubs with an upright growth habit.
Floribundas, as the name would suggest, have many flowers on each stem. They are a cross between hybrid teas and polyantha roses (low growing shrubs with large clusters of small flowers). Floribundas take the best from both parents. They tend to be medium-sized shrubs that produce many flowers all summer. Many floribundas have a fuller, shrub-like shape compared to the more vase-like, upright growth of many hybrid teas. If you live in a colder region then this rose is a good choice; with its polyantha heritage, it tends to be more cold hardy than many modern roses.
Grandifloras are a cross between Floribundas and Hybrid Teas. They have a little more of the hybrid tea blood in them and less polyantha, so they tend to be larger and more upright than the Floribundas (they often grow over six feet tall) and have long stems. They usually have three or four flowers per stem.
Miniature roses come in a variety of heights from 18 inches tall to 3 to 4 feet. Some miniature roses are climbers. What distinguishes them as miniature roses is that their flower form and foliage are miniature versions of other roses. Some of them are cascading and can be effectively used in containers or spilling over a stone wall. They are very hardy and easy to grow.
Climbing roses have no tendrils or means for climbing on their own, but they have large upright stems or canes that can be tied up and trained to grow on fences and pergolas. Many climbing roses have stiff, woody stems. Others, called ramblers, have thin, pliable stems which are ideal for growing up old trees or twining on an arbor or trellis. Roses operate on the principle of apical dominance; this simply means that the top growth will be pushing upward and will flower. For many of the climbing roses at the NYBG, we espalier or wrap them around posts. Taking the vertical stem and tying it horizontally means the apical dominance will be lost, which in turn encourages the side shoots (lateral shoots) to grow and flower. This is a simple way in which you can work with your climbers to get more blooms. Ramblers are generally once blooming and modern climbers are generally repeat blooming varieties.
Old-fashioned roses, also called old garden roses (Heritage Roses, Antique Roses), are the roses that existed before 1867 when the first Hybrid Tea rose was introduced. This large group includes wild species roses and old hybrids and cultivars such as Gallicas, Damasks, Albas, Centifolias, Moss roses, Chinas, Bourbons, Portlands, Hybrid Perpetuals, Teas and others. Most of these roses are large shrubs that flower only once in early summer and are known for their fragrant, intricate flowers. A numbers of these roses are also famous for their brilliant rose hips. These roses are pruned in a different fashion than modern roses, less hard and pruned after flowering. While a number of Old-fashioned roses are once bloomers, many of them, Chinas, Portlands, Bourbons, Mosses, Hybrid Perpetuals and Teas, have all gained repeat blooming characteristics. The virtues of many old-fashioned roses, from their flowers and fragrance to foliage and hips, are so exceptional that they are worth including in your garden.
Shrub roses are those that do not fall into any of the other categories. Some tend to be larger than Hybrid Teas and Floribundas and produce long canes. Others have been bred to be small and compact. Many modern shrub roses are hardy, disease-resistant and flower over a long period.
It is important to remember that for every rule, there is always an exception. When you see a large, upright rose with clusters of three flowers and then notice that some of the stems only contain one large bud, it’s probably just a Grandiflora pretending to be a Hybrid Tea. Every rule is just a rule of thumb.