Thursday, August 27, 2015

Different Kinds of Roses

Species Roses

These are roses as nature gave them to us. They are the species of the genus Rosa found growing naturally throughout the Northern Hemisphere. These roses are an enormously varied group of plants. They are vigorous, thriving on minimal maintenance, and tend to be extremely hardy and disease-resistant. It should be noted however, that there is variability within species. Some may be more tolerant than others. They range in size from ground cover types to very large upright growers and climbers. Their flowers can be very large and single or small and in clusters. Colors range from white to pink to crimson.

Species roses often have relatively simple, 5-petaled flowers followed by very colorful hips that last well into the winter, providing food for birds and winter color. Almost all are once-blooming in early summer. Perhaps the most familiar species for sale today is Rosa rugosa because of its superior hardiness, disease resistance, and extremely easy maintenance. The species has been widely hybridized. Species roses may not be for everyone. Rose enthusiasts like to include them into their collection for historical purposes as well as ease of maintenance.

Old European Garden Roses
There are five classes of roses that make up what is known as the most venerable group of cultivated roses. They are Gallica, Damask, Alba, Centifolia, and Mosses, and represent the hybrid groups that prevailed in European gardens prior to the widespread trade of Rosa chinensis in the eighteenth century. They are typically very fragrant and extremely cold-hardy (USDA zones 3-5). European roses tend to do better in cooler zones and may suffer when planted in zones 7 and higher. Also, contrary to common belief, the old European garden roses are not as disease-resistant as some report.


Gallicas
The Gallicas are the oldest cultivated Western rose surviving the fall of the Roman Empire by becoming naturalized wherever they had been planted. Gallicas tend to make bushy upright shrubs with fine prickles and dull green, heavily veined foliage that turns dark red in the fall. Gallicas are extremely hardy and are tolerant of soil not overly fertile. Fragrance is variable. Flower color is limited to stronger pink and purple-crimson shades. When grown on their own roots, Gallicas tend to sucker free, producing once-blooming compact shrubs growing to about 4 x 4 feet.

Damask
Damasks are among the most ancient of garden roses. They were cultivated by the Romans and may have died out had it not been for the European monasteries that cultivated roses for medicinal purposes. Damasks are taller than the Gallicas with paler, larger foliage. Their habit tends to be a graceful, somewhat arching plant that opens up under the weight of its flowers. Damasks are known for their strong, distinctive, "old rose" fragrance and their June flowering, which produces a large quantity of blooms used in the making of potpourri. Flower color ranges from white to deep pink. Flowers are borne in clusters of 3-5 or more. Damasks are extremely winter-hardy, have little problem with disease, and require little maintenance. Most bloom once in mid-summer.

Moss
The first Moss roses appeared as sports or mutations of Centifolia roses during the eighteenth century. Later they were joined by sports of Damask roses, which brought with them repeat blooming characteristics and darker colors. The name of this class comes from the fragrant, piney-scented glands that cover the buds, sepals, and pedicels, giving the plant a fuzzy appearance and a characteristic that is unique among roses. Plant size and garden habit are variable among the Moss roses. Most of them are very hardy, but they do tend to be highly prone to powdery mildew when conditions are favorable for this disease. All of the Moss roses bloom heavily in early summer, with some rebloom occurring late in the season. Flower color ranges from white to very dark crimson.

Alba
Alba roses are known as the "White Roses of Shakespeare." Albas are noted for their soft scent, sparse prickles, and deep blue-green foliage. Albas often reach a height of 7-8 feet, making them the tallest of the old European garden roses. Contrary to what their name suggests, blooms range from white to medium-pink. All Albas are once-blooming in mid-summer. Because of their height and foliage color, they make good backdrops for other plants. Albas are some of the toughest roses, offering extreme cold-hardiness and tolerance of considerable neglect. Albas will produce some bloom in the shade. They seem to grow very well and happily along a north-facing wall under the dappled shade of tall trees.

Centifolia
These are the "hundred petaled" roses or "cabbage roses" made famous by Dutch still life painters and are the result of hybridizing efforts by Dutch breeders in the seventeenth and eighteenth centuries. The Centifolias are distinctive shrubs, with large, coarse leaves, numerous prickles, and long, floppy canes. All are extremely fragrant. Centifolias are also very tough, winter-hardy plants that show few problems with fungal disease. Centifolias are one-time, mid-summer bloomers noted for the fullness and size of their flowers. They range in color from dark pink to lavender. Because their large blooms often weigh down the canes, many gardeners prefer to grow Centifolias as pillar roses or to train them over low fences to keep the flowers propped up.

Hardy Repeat-Blooming Old Roses
As can be seen, hardy old garden roses offer just about everything a gardener could ask for in a rose: extreme winter-hardiness, excellent tolerance to disease, exquisite blooms, and outstanding fragrance. The one thing that is lacking is recurrent bloom throughout the summer. Gardeners wanting to combine all of the qualities mentioned above with rebloom capabilities need only to look toward the Bourbons, Portlands, and Hybrid Perpetuals.


Bourbon
The Bourbon rose first appeared in the 1800s on the Isle of Bourbon (now Reunion) in the Indian Ocean. Bourbons bear large, full blooms that have a very heavy fragrance. They are extremely vigorous, producing shrubs that are big, wide, and very adaptable for training as pillar roses or on a fence. Most rebloom very reliably in colors that range from white to deep pink to scarlet. Bourbons are hardy to zone 4 and may survive colder climates with winter protection. Bourbons are occasionally subject to blackspot and mildew, which is not a major drawback because of the overall vigor of the shrub.

Portland
The Portland rose was discovered in 1775 by the Duchess of Portland. It was also known as Damask Perpetual and was considered a great discovery because it was among the very first reblooming garden roses. Portland roses are considered one of the very best old roses for the small garden because they tend to form shrubs that are only 3-4 feet tall and wide. In addition, the blooms are very highly scented. Blooms range in color from pink to red. Portlands have dark green foliage that holds up well and helps show off the blooms. Portlands may be a little tender for very cold USDA hardiness zones. Portlands benefit from winter protection in zones 4-5. It has been found that Portlands need about 2–3 years to get established in a new location before reliable bloom can be expected.

Hybrid Perpetual
The hybrid perpetual class is truly a hybrid. This class came about from the crossing of Bourbon roses with roses from just about every other class. Hybrid perpetuals are a varied group and were very popular during the Victorian era. Some varieties tend to be less reliable in their rebloom ability, and there is variation in height. Most hybrid perpetuals are tall-growing, up to 6 feet or more. This makes them excellent candidates for use as pillar roses or along a fence. Most hybrid perpetuals bloom heavily in the early summer followed by an occasional bloom in the summer and a moderate bloom in autumn. Colors range from white to crimson with exceptional fragrance. Blooms often look like full-blown hybrid teas. Hybrid perpetuals are only moderately hardy in zone 5, needing winter protection or special siting for best survival. They also suffer occasionally from blackspot and mildew. Hybrid perpetuals also perform better after they have had a chance to establish themselves in an area.




Modern Roses
The modern age of rose growing began officially when a new class of rose was developed from a tea/hybrid perpetual cross. The year was 1867, the hybridzer was Jean-Baptiste Guillot, the rose was 'La France,' and the class that was born was the hybrid tea. The most popular roses sold and the ones that have the most name recognition in the modern rose class are the hybrid tea, floribunda, and grandiflora.



Hybrid Tea
These roses typically have long pointed buds on long stems that offer an endless pallet of colors. All colors but blue and black can be found in hybrid teas. Perhaps of concern is the fact that in exchange for the perfect rose, with its perfect form and spectacular colors, an enormous amount of inbreeding has taken place. This has robbed many of the hybrid teas of the disease-resistance and winter hardiness that was found with many of the old roses. Another often mentioned is that hybrid teas no longer "smell like roses." In fact, many have lost their fragrance. However, with more than 6,000 varieties of hybrid teas available, it is possible to choose carefully from this pool and have hybrid teas that are vigorous and reliable. Many of the hybrid teas, floribundas, and grandifloras will require spray programs to maintain healthy foliage.

Grandiflora
"Grandiflora" is a term coined in 1954 to describe a new rose developed from a cross between hybrid tea and floribunda roses. Grandifloras tend to carry their flowers in clusters on top of tall stems. The flower size is a bit larger than floribunda. Grandifloras are one of the taller roses in the modern rose class, so they work well in the back of the border or as a screen. Grandiflora blooms are usually double but lack a striking fragrance. 'Queen Elizabeth' was the very first entry in the grandiflora class.

Floribunda
Floribundas came about when a polyantha rose was crossed with a hybrid tea rose. This was done in an effort to produce roses that were compact and had superior hardiness and disease resistance, something that was found to be lacking with hybrid teas. The American rose firm Jackson and Perkins coined the name floribunda and introduced the class at the 1939 New York World's Fair. Many floribundas produce an excellent display of flowers and are often used as low hedges, in borders, and in containers with other landscape plants.

Miniature
Miniatures are just that–small bushes with small flowers. Miniature roses have enjoyed a remarkable increase in popularity over the years. Many factors play into the increase, not the least of which is their adaptability to small gardens and containers and their dependability as extremely winter-hardy garden roses. Miniatures descended from a single dwarf China rose called‘Rouletii.' Miniatures were very popular with Chinese gardeners and only became popular in the United States when breeding programs started to blossom just after World War II.

Miniatures range in height from 3 inches to 18 inches. Most are continuous bloomers with little or no fragrance. As a class, they are excellent for containers, borders, rock gardens, and other small spaces. Miniatures are almost always grown on their own root, not grafted. As a result, they are extremely winter-hardy. Much of the hybridization work on miniatures is now done in the United States producing many of the better contemporary varieties.

A quote from David Austin, a prominent English rose breeder, sums up the miniature rose revolution: "It is an odd fact that the miniature roses have received more attention in the land of the‘bigger and better,' the United States, than anywhere else." Maybe it's time to think of miniatures not just as plants growing on windowsills or in clay pots in grandmother's kitchen, but as versatile garden plants.

Shrub Roses
This class of rose is a "catch all" for roses that do not fit well in other classes. This "duke's mixture" of a class includes everything from hybrid rugosas developed in the late 1800s, to hybrid musks developed in the 1900s, to floribundas and the latest and newest introductions in landscape roses.

"Shrub rose" may be a poor choice of words, and as a result the term is largely artificial because all roses are in fact shrubs –just as is a lilac or a forsythia. "Shrub," as applied to roses, is more a case of definition by usage rather than by description.

Shrub roses are noted for their well-rounded shape, their exceptional winter hardiness, and their better than average disease resistance.

Today's gardeners are finding the task of maintaining quality roses a bit easier with the introduction of many shrub roses into the market. Shrub roses are also very free-flowering, producing a good supply of fragrant flowers all summer. Shrub roses are bred and selected for planting "outside" the rose garden, blending well into a mixed border of flowers, as landscape hedges, and into the landscape at large.

One may find reference to both old and modern shrub roses. Both classes have merit. The old shrub roses are tall (6+ feet) and need a lot of space. They are also extremely hardy and pest-resistant. Modern shrub roses tend to be more compact while still maintaining the qualities you would find in older shrub roses. Modern shrub roses can be found carrying class names and terms such as "English Garden Roses," "David Austin Roses," "Sub-Zero Roses," "Dr. Buck Roses," "Kordesii Roses," "Canadian Explorer Roses," "Parkland Roses," "Meidiland Roses," "Hybrid Rugosa," and "Hybrid Musk."

Hybrid Rugosa
Rugosa roses are a class of nineteenth-century origin. But the potential of using Rosa rugosa as a parent in breeding programs only surfaced a few decades ago. This produced a wealth of plant material that has resulted in one of the larger and more important classes within the shrub rose group.

The result is a rose with exceptional cold tolerance and disease resistance, handsomely wrinkled foliage of the rugosa parents, but with a wider variety of flower form and color and a plant habit that ranges from compact shrubs to vigorous climbers. Rugosas make perhaps the ideal low-maintenance landscape rose. In fact, applying fungicides often results in very severe leaf injury and loss. Rugosa roses can tolerate drier conditions without much reduction in bloom and can be grown in light shade. Add to this their ability to produce an exceptional display of hips in the fall and attractive fall color and you have a rose that most home gardeners welcome.

Two outstanding strains of hybrid rugosa roses are the 'Canadian Explorer' series and the 'Parkland' series. Both of these are products of Canadian rose breeding programs. The 'Explorer' roses were bred in Ottawa, Ontario and named after famous Canadian explorers. The 'Parkland' roses came from Morden Station in Morden, Manitoba, Canada. 'Parkland' roses differ somewhat from 'Explorer' roses in that the 'Parklands' may freeze to the snow line or to the ground. If they are on their own root, they will regrow and flower very well. This freezing back tends to make 'Parklands' a smaller-statured plant perfect for the perennial garden or smaller urban garden. There are a number of 'Explorers' that make excellent climbers for northern gardens.

Some key points with 'Explorer' and 'Parkland' roses are: (1) they tend to do better when not fertilized to excess; heavy fertilization prompts lush, soft growth. (2) Because the 'Explorers' have rugosa heritage, they do not like fungicide applications; treatment with fungicides for blackspot will make leaves deteriorate faster. (3) Many of the hybrid rugosas perform better in cooler climates. In areas where it gets very hot, performance tends to decline. There are however a number of varieties that are more heat tolerant. Many rugosas are also tolerant of salt spray, which makes them good candidates for planting in areas where road salt spray is a problem.

Hybrid Musk Roses
The hybrid musk roses came to us by way of England in the early 1900s. Hybrid musks are often overlooked as a class of rose for the garden, but they offer much. Hybrid musks are generally large (6+ feet) and have an arching habit. Most all are hardy to USDA zones 5-6. They have attractive leathery foliage and rebloom reliably through the summer in large trusses of small- to medium-sized flowers with a strong fragrance. Hybrid musks have outstanding disease resistance and are exceptionally tolerant of filtered shade, blooming well with as little as 5 hours of direct sunlight. Most can be used as pillar roses or as short climbers for walls and fences.


Roses with Long Canes
Roses in this class go under a variety of names: ground cover roses, climbers, ramblers and pillar roses. The common thread is that all of them have very long canes that can be directed along the ground or over structures. No rose truly climbs, as they don't have tendrils or other devices to help grasp on supports. Many of the climbers offered in garden centers are sports or mutations of standard hybrid teas. As a result, their hardiness is very questionable in colder climates, where they often freeze to the ground each year. As a result, the reason gardeners grow climbers–to cover a structure–is lost; the process has to start new each year. Climbers and ramblers are distinguished by their bloom and growth habit. Climbers generally bear large flowers singly or in clusters on very heavy canes. Many climbers have periodic rebloom in late summer or early autumn. In addition, the more horizontal a climber can be trained, the more blooms it will produce. Climbers range in height from 8-25 feet. Rambling roses are almost all once-blooming with small flowers in large clusters. The canes are generally very slender, flexible, and easily trained. Ramblers get very large, often growing to 15-25 feet. Rambling roses were favorites with Victorian gardeners.

Gardeners in colder climates often have fewer choices when selecting climbers due to the difficulty of successfully overwintering the long canes. There are a number of excellent hardy 'Kordesii' and 'Canadian Explorer' types grown as climbers that overwinter very nicely. A number of roses found in the other classes can be treated as climbers, pillars, or groundcover roses by virtue of the fact that they have long canes that with support can be trained upward.

David Austin Roses
Not considered an official class, the English roses have become very popular through the work of breeder David Austin. English roses are meant to combine old rose style and scent with modern rose habit and rebloom. All of this comes at the expense of the typical hardiness and disease resistance one would find in the "old roses." USDA zones 5B-6 seem to be the limit for many of these introductions. However, with proper siting and winter protection you may get away with planting in colder zones. Many of the varieties offered tend to look more like hybrid teas in growth habit than old garden roses. This is why Austin suggests grouping 2 to 3 plants on 18-inch centers for the full old rose bush look. A site with light shade coming in the mid-afternoon helps blooms to retain their fresh look longer.

Dr. Griffith Buck Roses
Dr. Griffith Buck was an Iowa State University rose hybridizer. He developed a number of varieties that are excellent landscape roses because of their winter hardiness and disease resistance. Dr. Buck applied the Darwinian principle of survival of the fittest to his roses. If his roses couldn't survive the winter without protection and maintain good foliage without fungicides, he felt they didn't deserve to be introduced on the market. Just another pretty face didn't count much in his breeding program. His roses are sometimes referred to as "sub-zero" roses.