Roses

By Dr. William C. Welch
Professor and Landscape Horticulturist
Texas A&M University, College Station, Texas

The rose is America’s favorite flower. The genus Rosa includes numerous species, including some natives. The major appeal of roses is in the color and beauty of the blossoms. Some bloom almost year round while others provide massive displays for several or more weeks.

There has been considerable question over the landscape value of roses. Actually, there are some roses that lend themselves very well to use as vines, masses, or even specimen use. Hybrid Tea roses, which are the most common class of roses currently available, are best grown in well prepared, sunny beds where they receive at least half a day of sun and good air circulation. Hybrid Tea roses require a regular spray program for prevention and control of black spot and mildew diseases.

Garden roses require very little cold weather to satisfy their dormancy requirements. This means that it is possible to successfully grow roses in all parts of Texas. They are best transplanted during the winter from late December through February. Many garden centers order bare root plants for delivery in December and January. Immediately upon arrival, these plants are potted in containers. This method allows the planting season to be extended later into the spring. Most rosarians like to set out new plants during January and February so that the root systems can be well established before the hot weather arrives.

Roses are classified according to growth and flowering characteristics. A brief description of the most common classifications should be helpful in planning their use in the landscape.

Hybrid Teas
Because of their almost continuous flowering habit, Hybrid Teas are often called monthly or everblooming roses. They are the result of crossing two old-fashioned rose classes, the Hybrid Perpetual and the Tea rose from China which gave the repeat blooming trait. In general, the buds are pointed, long, and borne one per stem. Hybrid Teas are the most common class sold today but are generally grown for cut flowers rather than as landscape plants.

Floribundas
The Floribundas originated from crossing the Hybrid Tea with Polyantha roses. Plants are vigorous with large masses of well shaped flowers that resemble miniature Hybrid Teas. With proper care Floribundas can provide an almost continuous source of landscape color. They are most effective in mass displays of the same variety. Floribunda roses are usually more compact in growth form than Hybrid Teas.



Polyantha 'Marie Daly'


Polyanthas
Polyanthas produce small flowers in large clusters and are primarily used for mass plantings or borders. Probably the most popular variety available in this class is ‘Cecile Brunner,’ which is often called the “Sweetheart Rose” and is available in both climbing and bush form. There are very few Polyanthas on the market today because Floribundas seem to have more appeal and are more widely available.

Grandifloras
This is a relatively new classification which resulted from crosses between Hybrid Tea and Floribunda varieties. Grandifloras are usually very vigorous plants. ‘Queen Elizabeth’ is probably the most popular rose in this class.

Climbing and Pillar Roses
Many of the popular varieties of the classes previously described have climbing forms. There are, however, some varieties considered natural climbers which include such popular choices as ‘Blaze,’ ‘New Dawn,’ and ‘Lady Banks.’ Climbers are usually very vigorous an require different pruning practices from those of bush types. Most climbers should be pruned after they bloom in the spring, since many of them flower primarily on last year’s wood.

Old Garden Roses
This is really more of a generalized grouping than a class of roses. Included are China, Hybrid Perpetual, Tea, Moss, Damask, Bourbon and Noisette roses. Recent years have seen considerable interest in may of these plants. Part of their popularity is due to nostalgia and interest in historical plantings. Old rose enthusiasts quickly point to the superior fragrance, hardiness, growth habit, and disease resistance of some of the old varieties that may have been lost or weakened in the hybridization process of newer varieties.

Whatever the reason, there is a definite emerging interest in old roses in Texas as well as the nation. Catalogs from nurseries specializing in old roses have become popular references and sources of information for the older varieties.

Miniature Roses
Most of these plants grow no more than 16 to 36 inches in height. They are natural (genetic) dwarfs and have become popular in recent years. Unlike most other rose classes, miniatures are usually grown as and are valuable for mass landscape plantings or container culture. Their growth requirements are similar to those of other roses, and most varieties need to be sprayed regularly to control black spot and spider mites.

There are hundreds of varieties available with new ones appearing on a regular basis. A major reason for the popularity of miniature roses is their ease of propagation. Cuttings can be rooted during the cooler months, and older plants can usually be divided. Most miniatures bloom profusely and regularly.

Own-root roses are propagated from cuttings rather than grafted or budded onto rootstocks. This is the method used by our ancestors to propagate roses and is still popular today. Many of the modern roses don’t seem to be vigorous enough to do well as own-root plants but most miniature roses and many old garden roses are offered for sale as own-root plants. An advantage is that many roses seem to be more vigorous and live longer when grown from cuttings. Own-root roses are less likely to be permanently damaged by excessive cold because when they are frozen above ground and sprout out from below the next spring they will remain the original variety instead of the root stock. For additional information on rooting roses from cuttings click on Rose Propagation.

Purchasing Roses
Roses are readily available during the late winter and spring. Packaged roses are often featured in discount and grocery stores as well as some garden centers. There is nothing really wrong with this method of handling roses; but if they are stored or displayed in warm temperatures, sprouting occurs almost immediately. Sprouting severely weaken the plant and may result in poor performance or even death.

Bare root roses are often available from mail order nurseries and are usually packed in plastic with some sort of moisture retaining material around the roots to further prevent drying. It is important to plant these roses as soon as possible upon arrival.; if planting is to be delayed, the rose should be “heeled in” in a good garden soil and kept moist until planting.

Roses in containers are featured by many garden centers in Texas. It is important that the container be large enough to adequately hold the root system. A one-gallon container is usually too small for a normal sized, two-year-old bush. Two or three-gallon containers are much better. Some nurseries use containers that will decompose soon after planting and recommend that the entire container be set into the rose bed. Seasoned rose growers usually prefer to remove the plant from the container so that the root system can more quickly become established in the surrounding soil.

Roses are usually graded to standardized criteria. This includes #1, #1-1/2, and #2 grades. Homeowners are probably wise to choose #1 or #1-1/2 grade, since the vigor and size of these plants is usually superior.


This article appeared in Horticulture Update - January-February 2001, edited by Dr. William C. Welch, and produced by Extension Horticulture, Texas Agricultural Extension Service, The Texas A&M University System, College Station, Texas.

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