Rose

Plant Characteristics

Habit		shrub
Lifespan:	⌛	perennial

Cultivation

Exposure:	☼	sun, part-sun
Water:	◍	moderate
Features:	✓	flowers, fragrance, cut flowers

Scientific Names

Rosaceae >

Rosa >

A rose is a perennial flowering shrub or vine of the genus Rosa, within the family Rosaceae, that contains over 100 species. The species form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp thorns. Most are native to Asia, with smaller numbers of species native to Europe, North America, and northwest Africa. Natives, cultivars and hybrids are all widely grown for their beauty and fragrance. [1]

The leaves are alternate and pinnately compound, with sharply toothed oval-shaped leaflets. The plants fleshy edible fruit is called a rose hip. Rose plants range in size from tiny, miniature roses, to climbers that can reach 20 metres in height. Species from different parts of the world easily hybridize, which has given rise to the many types of garden roses.

Species

Rosa multiflora

Some representative rose species

• Rosa canina: Dog Rose, Briar Bush
• Rosa chinensis: China Rose
• Rosa dumalis: Glaucous Dog Rose
• Rosa gallica: Gallic Rose, French Rose
• Rosa gigantea (syn. R. x odorata gigantea)
• Rosa glauca (syn. R. rubrifolia): Redleaf Rose
• Rosa laevigata (syn. R. sinica): Cherokee Rose, Camellia Rose, Mardan Rose
• Rosa majalis: Cinnamon Rose
• Rosa moschata: Musk Rose
• Rosa multiflora: Multiflora Rose
• Rosa persica (syn. Hulthemia persica, R. simplicifolia)
• Rosa pimpinellifolia: Burnet Rose
• Rosa roxburghii: Chestnut Rose, Burr Rose
• Rosa rubiginosa (syn. R. eglanteria): Eglantine, Sweet Briar
• Rosa rugosa: Rugosa Rose, Japanese Rose
• Rosa stellata: Gooseberry Rose, Sacramento Rose
• Rosa virginiana (syn. R. lucida): Virginia Rose

Cultivation

Rosa canina hips

The leaves of most species are 5–15 centimetres long, pinnate, with (3–) 5–9 (–13) leaflets and basal stipules; the leaflets usually have a serrated margin, and often a few small prickles on the underside of the stem. The vast majority of roses are deciduous, but a few (particularly in Southeast Asia) are evergreen or nearly so.

The flowers of most species roses have five petals, with the exception of Rosa sericea, which usually has only four. Each petal is divided into two distinct lobes and is usually white or pink, though in a few species yellow or red. Beneath the petals are five sepals (or in the case of some Rosa sericea, four). These may be long enough to be visible when viewed from above and appear as green points alternating with the rounded petals. The ovary is inferior, developing below the petals and sepals.

The aggregate fruit of the rose is a berry-like structure called a rose hip. Rose species that produce open-faced flowers are attractive to pollinating bees and other insects, thus more apt to produce hips. Many of the domestic cultivars are so tightly petalled that they do not provide access for pollination. The hips of most species are red, but a few (e.g. Rosa pimpinellifolia) have dark purple to black hips. Each hip comprises an outer fleshy layer, the hypanthium, which contains 5–160 "seeds" (technically dry single-seeded fruits called achenes) embedded in a matrix of fine, but stiff, hairs. Rose hips of some species, especially the Dog Rose (Rosa canina) and Rugosa Rose (Rosa rugosa), are very rich in vitamin C, among the richest sources of any plant. The hips are eaten by fruit-eating birds such as thrushes and waxwings, which then disperse the seeds in their droppings. Some birds, particularly finches, also eat the seeds.

While the sharp objects along a rose stem are commonly called "thorns", they are actually prickles — outgrowths of the epidermis (the outer layer of tissue of the stem). True thorns, as produced by e.g. Citrus or Pyracantha, are modified stems, which always originate at a node and which have nodes and internodes along the length of the thorn itself. Rose prickles are typically sickle-shaped hooks, which aid the rose in hanging onto other vegetation when growing over it. Some species such as Rosa rugosa and R. pimpinellifolia have densely packed straight spines, probably an adaptation to reduce browsing by animals, but also possibly an adaptation to trap wind-blown sand and so reduce erosion and protect their roots (both of these species grow naturally on coastal sand dunes). Despite the presence of prickles, roses are frequently browsed by deer. A few species of roses only have vestigial prickles that have no points.

Pruning

Rose pruning, sometimes regarded as a horticultural art form, is largely dependent on the type of rose to be pruned, the reason for pruning, and the time of year it is at the time of the desired pruning.

Most Old Garden Roses of strict European heritage (albas, damasks, gallicas, etc.) are shrubs that bloom once yearly, in late spring or early summer, on two-year-old (or older) canes. As such, their pruning requirements are quite minimal, and are overall similar to any other analogous shrub, such as lilac or forsythia. Generally, only old, spindly canes should be pruned away, to make room for new canes. One-year-old canes should never be pruned because doing so will remove next year's flower buds. The shrubs can also be pruned back lightly, immediately after the blooms fade, to reduce the overall height or width of the plant. In general, pruning requirements for OGRs are much less laborious and regimented than for Modern hybrids.

Modern hybrids, including the hybrid teas, floribundas, grandifloras, modern miniatures, and English roses, have a complex genetic background that almost always includes China roses (R. chinensis). China roses were evergrowing, everblooming roses from humid subtropical regions that bloomed constantly on any new vegetative growth produced during the growing season. Their modern hybrid descendants exhibit similar habits: Unlike Old Garden Roses, modern hybrids bloom continuously (until stopped by frost) on any new canes produced during the growing season. They therefore require pruning away of any spent flowering stem, in order to divert the plant's energy into producing new growth and thence new flowers.

Additionally, Modern Hybrids planted in cold-winter climates will almost universally require a "hard" annual pruning (reducing all canes to 8"–12" in height) in early spring. Again, because of their complex China rose background, Modern Hybrids are typically not as cold-hardy as European OGRs, and low winter temperatures often desiccate or kill exposed canes. In spring, if left unpruned, these damanged canes will often die back all the way to the shrub's root zone, resulting in a weakened, disfigured plant. The annual "hard" pruning of hybrid teas, floribundas, etc. should generally be done in early spring; most gardeners coincide this pruning with the blooming of forsythia shrubs. Canes should be cut about 1/2" above a vegetative bud (identifiable as a point on a cane where a leaf once grew).

For both Old Garden Roses and Modern Hybrids, any weak, damaged or diseased growth should be pruned away completely, regardless of the time of year. Any pruning of any rose should also be done so that the cut is made at a forty five degree angle above a vegetative bud. This helps the pruned stem callus over more quickly, and also mitigates moisture buildup over the cut, which can lead to disease problems.

For all general rose pruning (including cutting flowers for arrangements), sharp secateurs (hand-held, sickle-bladed pruners) should be used to cut any growth 1/2" or less in diameter. For canes of a thickness greater than 1/2", pole loppers or a small handsaw are generally more effective; secateurs may be damaged or broken in such instances.

Deadheading

Deadheading is the simple practice of manually removing any spent, faded, withered, or discoloured flowers from rose shrubs over the course of the blooming season. The purpose of deadheading is to encourage the plant to focus its energy and resources on forming new offshoots and blooms, rather than in fruit production. Deadheading may also be performed, if spent flowers are unsightly, for aethestic purposes. Roses are particularly responsive to deadheading.

Rose types

Rose-picking in the Rose Valley near the town of Kazanlak in Bulgaria, 1870s, engraving by Austro-Hungarian traveller F. Kanitz

Roses are popular garden shrubs, as well as the most popular and commonly sold florists' flowers. In addition to their great economic importance as a florists crop, roses are also of great value to the perfume industry.

Many thousands of rose hybrids and cultivars have been bred and selected for garden use; most are double-flowered with many or all of the stamens having mutated into additional petals. As long ago as 1840 a collection numbering over one thousand different cultivars, varieties and species was possible when a rosarium was planted by Loddiges nursery for Abney Park Cemetery, an early Victorian garden cemetery and arboretum in England.

Twentieth-century rose breeders generally emphasized size and colour, producing large, attractive blooms with little or no scent. Many wild and "old-fashioned" roses, by contrast, have a strong sweet scent.

Roses thrive in temperate climates, though certain species and cultivars can flourish in sub-tropical and even tropical climates, especially when grafted onto appropriate rootstock.

There is no single system of classification for garden roses. In general, however, roses are placed in one of three main groups:

Wild Roses

The wild roses includes the species listed above and some of their hybrids.

Old Garden Roses

Most Old Garden Roses are classified into one of the following groups. In general, Old Garden Roses of European or Mediterranean origin are once-blooming shrubs, with notably fragrant, double-flowered blooms primarily in shades of white, pink and red. The shrubs' foliage tends to be highly disease-resistant, and they generally bloom only on two-year-old canes.

Alba

Rosa x alba 'Alba Semiplena', an Alba rose

Rosa 'Maiden's Blush', an Alba rose

Literally "white roses", derived from R. arvensis and the closely allied R. alba. These are some of the oldest garden roses, probably brought to Great Britain by the Romans. The shrubs flower once yearly in the spring with blossoms of white or pale pink. The shrubs frequently feature gray-green foliage and a climbing habit of growth . Examples: 'Alba Semiplena', 'White Rose of York'.

Gallica

The gallica roses have been developed from R. gallica, which is a native of central and southern Europe. They flower once in the summer over low shrubs rarely over 4' tall. Unlike most other once-blooming Old Garden Roses, the gallica class includes shades of red, maroon and deep purplish crimson. Examples: 'Cardinal de Richelieu', 'Charles de Mills', 'Rosa Mundi' (R. gallica versicolor).

Damask

Robert de Brie is given credit for bringing damask roses from Persia to Europe sometime between 1254 and 1276, although there is evidence from ancient Roman frescoes that at least one damask rose, the Autumn Damask, existed in Europe for hundreds of years prior. Summer damasks (crosses between gallica roses and R. phoenicea) bloom once in summer. Autumn damasks (Gallicas crossed with R. moschata) bloom again later, in the autumn. Shrubs tend to have rangy to sprawly growth habits and vicious thorns. The flowers typically have a more loose petal formation than gallicas, as well as a stronger, tangy fragrance. Examples: 'Ispahan', 'Madame Hardy'.

Centifolia or Provence

Centifolia roses, raised in the seventeenth century in the Netherlands, are named for their "one hundred" petals; they are often called "cabbage" roses due to the globular shape of the flowers. The result of damask roses crossed with albas, the centifolias are all once-flowering. As a class, they are notable for their inclination to produce mutations of various sizes and forms, including moss roses and some of the first miniature roses (see below) . Examples: 'Centifolia', 'Paul Ricault'.

Moss

Mutations of primarily centifolia roses (or sometimes damasks), moss roses have a mossy excrescence on the stems and sepals that often emits a pleasant woodsy or balsam scent when rubbed. Moss roses are cherised for this unique trait, but as a group they have contributed nothing to the development of new rose classifications. Moss roses with centifolia background are once-flowering; some moss roses exhibit repeat-blooming, indicative of Autumn Damask parentage. Example: 'Common Moss' (centifolia-moss), 'Alfred de Dalmas' (Autumn Damask moss).

China

The China roses were grown in East Asia for thousands of years and finally reached Western Europe in the late 1700s. Compared to the aforementioned European rose classes, the Chinese roses had smaller, less fragrant, more poorly formed blooms carried over twiggier, more cold-sensitive shrubs. Yet they possessed the amazing ability to bloom repeatedly throughout the summer and into late autumn, unlike their European counterparts. This made them highly desirable for hybridization purposes in the early 1800s. The flowers of China roses were also notable for their tendency to "suntan," or darken over time — unlike the blooms of European roses, which tended to fade after opening. Four China roses ('Slater's Crimson China', 1792; 'Parsons' Pink China', 1793; 'Hume's Blush China', 1809; and 'Parks' Yellow Tea Scented China', 1824) were brought to Europe in the late eighteenth and early nineteenth centuries. This brought about the creation of the first classes of repeat-flowering Old Garden Roses, and later the Modern Garden Roses. Examples: 'Old Blush China', 'Mutabilis' (butterfly rose).

Portland

The Portland roses represent the first group of crosses between China roses and European roses, specifically gallicas and damasks. They were named after the Duchess of Portland who received (from Italy in 1800) a rose then known as R. paestana or 'Scarlet Four Seasons' Rose' (now known simply as 'The Portland Rose'). The whole class of Portland roses was thence developed from that one rose. The first repeat-flowering class of rose with fancy European-style blossoms, they are mostly descended from hybrids between damask and China roses. The plants tend to be fairly short and shrubby, with proportionately short flower stalks. Example: 'James Veitch', 'Rose de Rescht', 'Comte de Chambourd'.

Bourbon

Rosa 'Climbing Souvenir de la Malmaison', a Bourbon rose

'Rosa 'Zéphirine Drouhin', a Bourbon rose

Bourbons originated on l'Île de Bourbon (now called Réunion) off the coast of Madagascar in the Indian Ocean. They are most likely the result of a cross between the Autumn Damask and the 'Old Blush' China rose, both of which were frequently used as hedging materials on the island. They flower repeatedly over vigorous, frequently semi-climbing shrubs with glossy foliage and purple-tinted canes. They were first Introduced in France in 1823. Examples: 'Louise Odier', 'Mme. Pierre Oger', 'Zéphirine Drouhin'.

Noisette

The first Noisette rose was raised as a hybrid seedling by a South Carolina rice planter named John Champneys. Its parents were the China Rose 'Parson's Pink' and the autumn-flowering musk rose (Rosa moschata), resulting in a vigorous climbing rose producing huge clusters of small pink flowers from spring to fall. Champneys sent seedlings of his rose (called 'Champneys' Pink Cluster') to his gardening friend, Philippe Noisette, who in turn sent plants to his brother Louis in Paris, who then introduced 'Blush Noisette' in 1817. The first Noisettes were small-blossomed, fairly winter-hardy climbers, but later infusions of Tea rose genes created a Tea-Noisette subclass with larger flowers, smaller clusters, and considerably reduced winter hardiness. Examples: 'Blush Noisette', 'Mme. Alfred Carriere' (Noisette), 'Marechal Niel' (Tea-Noisette). (See French and German articles on Noisette roses)

Tea

The result of crossing two of the original China roses ('Hume's Blush China' and 'Parks' Yellow Tea Scented China') with various Bourbons and Noisette roses, tea roses are considerably more tender than other Old Garden Roses (due to cold-tender Rosa gigantea in the ancestry of the 'Parks' Yellow' rose). The teas are repeat-flowering roses, named for their fragrance being reminiscent of Chinese black tea (although this is not always the case). The color range includes pastel shades of white, pink and yellow, and the petals tend to roll back at the edges, producing a petal with a pointed tip. The individual flowers of many cultivars are semi-pendent and nodding, due to weak flower stalks. Examples: 'Lady Hillingdon', 'Maman Cochet'.

Hybrid Perpetual

The dominant class of roses in Victorian England, hybrid perpetuals first emerged in 1838 and were derived to a great extent from the Bourbons. They became the most popular garden and florist roses of northern Europe at the time, as the tender tea roses would not thrive in cold climates. The "perpetual" in the name hints at repeat-flowering, but many varieties of this class had poor reflowering habits; the tendency was for a massive spring bloom, followed by either scattered summer flowering, a smaller autumn burst, or sometimes nothing at all until next spring. Due to a limited color palette (white, pink, red) and lack of reliable repeat-bloom, the hybrid perpetuals were ultimately overshadowed by their own descendants, the Hybrid Teas. Examples: 'Ferdinand Pichard', 'Reine Des Violettes', 'Paul Neyron'.

Hybrid Musk

The hybrid musk group was primarily developed by Rev. Joseph Pemberton, a British rosarian, in the first decades of the 20th century, based upon 'Aglaia', a 1896 cross by Peter Lambert. A seedling of this rose, 'Trier', is considered to the be foundation of the class. The genetics of the class are somewhat obscure, as some of the parents are unknown. Rose multiflora, however, is known to be one parent, and R. moschata (the musk rose) also figures in its heritage, though it is considered to be less important than the name would suggest. Hybrid musks are disease-resistant, remontant and generally cluster-flowered, with a strong, characteristic "musk" scent. Examples include 'Buff Beauty' and 'Penelope'.

Bermuda "Mystery" Roses

A group of several dozen "found" roses that have been grown in Bermuda for at least a century. The roses have significant value and interest for those growing roses in tropical and semi-tropical regions, since they are highly resistant to both nematode damage and the fungal diseases that plague rose culture in hot, humid areas, and capable of blooming in hot and humid weather. Most of these roses are likely Old Garden Rose cultivars that have otherwise dropped out of cultivation, or sports thereof. They are "mystery roses" because their "proper" historical names have been lost. Tradition dictates that they are named after the owner of the garden where they were rediscovered.

Hybrid Rugosa

Derived from the R. Rugosa species, these vigorous roses are extremely hardy with excellent disease resistance. Most are extremely fragrant, repeat bloomers with moderately double flat flowers. The defining characteristic of a Hybrid Rugosa rose is its wrinkly leaves, but some hybrids do lack this trait. These roses will often set hips. Examples include 'Hansa' and 'Roseraie de l'Häy'.

Miscellaneous

There are also a few smaller classes (such as Scots, Sweet Brier) and some climbing classes of old roses (including Ayrshire, Climbing China, Laevigata, Sempervirens, Boursault, Climbing Tea, and Climbing Bourbon). Those classes with both climbing and shrub forms are often grouped together.

Modern Garden Roses

File:Rose at University of the Pacific.JPG

A modern garden rose at University of the Pacific (United States).

Rosa 'Cajun Sunrise', a modern Hybrid Tea rose

Classification of modern roses can be quite confusing because many modern roses have old garden roses in their ancestry and their form varies so much. The classifications tend to be by growth and flowering characteristics, such as "large-flowered shrub", "recurrent, large-flowered shrub", "cluster-flowered", "rambler recurrent", or "ground-cover non-recurrent". The following includes the most notable and popular classifications of Modern Garden Roses:

Hybrid Tea

The favourite rose for much of the history of modern roses, hybrid teas were initially created by hybridizing Hybrid Perpetuals with Tea roses in the late 1800s. 'La France,' created in 1867, is universally acknowledged as the first indication of a new class of roses. Hybrid teas exhibit traits midway between both parents: hardier than the teas but less hardy than the hybrid perpetuals, and more everblooming than the hybrid perpetuals but less so than the teas. The flowers are well-formed with large, high-centered buds, and each flowering stem typically terminates in a single shapely bloom. The shrubs tend to be stiffly upright and sparsely foliaged, which today is often seen as a liability in the landscape. The hybrid tea class is important in being the first class of roses to include genes from the old Austrian brier rose (Rosa foetida). This resulted in an entirely new color range for roses: shades of deep yellow, apricot, copper, orange, true scarlet, yellow bicolors, lavender, gray, and even brown were now possible. The new color range did much to skyrocket hybrid tea popularity in the 20th century, but these colors came at a price: Rosa foetida also passed on a tendency toward disease-susceptibility, scentless blooms, and an intolerance of pruning, to its descendants. Hybrid teas became the single most popular class of garden rose of the 20th century; today, their reputation as being more high maintenance than many other rose classes has led to a decline in hybrid tea popularity among gardeners and landscapers in favor of lower-maintenance "landscape" roses. The hybrid tea remains the standard rose of the floral industry, however, and is still favoured in small gardens in formal situations. Examples: 'Peace' (yellow), 'Mr. Lincoln' (red), 'Double Delight' (multicolors).

Polyantha

Literally "many-flowered" roses, from the Greek "poly" (many) and "anthos" (flower). Originally derived from crosses between two East Asian species (Rosa chinensis and R. multiflora), polyanthas first appeared in France in the late 1800s alongside the hybrid teas. They featured short plants — some compact, others spreading in habit — with tiny blooms (1" in diameter on average) carried in large sprays, in the typical rose colors of white, pink and red. Their main claim to fame was their prolific bloom: From spring to fall, a healthy polyantha shrub might be literally covered in flowers, creating a strong color impact in the landscape. Polyantha roses are still regarded as low-maintenance, disease-resistant garden roses today, and remain popular for that reason. Examples: 'Cecile Brunner', 'The Fairy', 'Red Fairy'.

Floribunda

Rosa 'Borussia', a modern Floribunda rose

Rose breeders quickly saw the value in crossing polyanthas with hybrid teas, to create roses that bloomed with the polyantha profusion, but with hybrid tea floral beauty and color range. In 1909, the first polyantha/hybrid tea cross, 'Gruss an Aachen,' was created, with characteristics midway between both parent classes. As the larger, more shapely flowers and hybrid-tea-like growth habit separated these new roses from polyanthas and hybrid teas alike, a new class was created and named Floribunda, Latin for "many-flowering." Typical floribundas feature stiff shrubs, smaller and bushier than the average hybrid tea but less dense and sprawling than the average polyantha. The flowers are often smaller than hybrid teas but are carried in large sprays, giving a better floral effect in the garden. Floribundas are found in all hybrid tea colors and with the classic hybrid tea-shaped blossom, sometimes differing from hybrid teas only in their cluster-flowering habit. Today they are still used in large bedding schemes in public parks and similar spaces. Examples: 'Dainty Maid', 'Iceberg', 'Tuscan Sun'.

Grandiflora

Grandifloras (Latin for "large-flowered") were the class of roses created in the mid 1900s to designate back-crosses between hybrid teas and floribundas that fit neither category — specifically, the 'Queen Elizabeth' rose, which was introduced in 1954. Grandiflora shrubs are typically larger than either hybrid teas or floribundas, and feature hybrid tea-style flowers borne in small clusters of three to five, similar to a floribunda. Grandifloras maintained some popularity from about the 1950s to the 1980s but today they are much less popular than either the hybrid teas or the floribundas. Examples: 'Queen Elizabeth', 'Comanche,' 'Montezuma'.

Miniature

Meillandine (a miniature rose) in a terra cotta flowerpot

All of the classes of Old Garden Roses—gallicas, centifolias, etc.—had corresponding miniature forms, although these were once-flowering just as their larger forms were. As with the standard-sized varieties, miniature Old Garden roses were crossed with repeat-blooming Asian species to produce everblooming miniature roses. Today, miniature roses are represented by twiggy, repeat-flowering shrubs ranging from 6" to 36" in height, with most falling in the 12"–24" height range. Blooms come in all the hybrid tea colours; many varieties also emulate the classic high-centered hybrid tea flower shape. Miniature roses are often marketed and sold by the floral industry as houseplants, but it is important to remember that these plants are largely descended from outdoor shrubs native to temperate regions; thus, most miniature rose varieties require an annual period of cold dormancy to survive. (Examples: Petite de Hollande (Miniature Centifolia, once-blooming), Cupcake (Modern Miniature, repeat-blooming).)

Climbing/Rambling

As is the case with Miniature roses, all aforementioned classes of roses, both Old and Modern, have "climbing" forms, whereby the canes of the shrubs grow much longer and more flexible than the normal ("bush") forms. In the Old Garden Roses, this is often simply the natural growth habit of many cultivars and varieties; in many Modern roses, however, climbing roses are the results of spontaneous mutations. For example, 'Climbing Peace' is designated as a "Climbing Hybrid Tea," for it is genetically identical to the normal "shrub" form of the 'Peace' hybrid tea rose, except that its canes are long and flexible, i.e. "climbing." Most Climbing roses grow anywhere from 8'–20' in height and exhibit repeat-bloom. Rambler roses, although technically a separate class, are often lumped together with climbing roses. They also exhibit long, flexible canes, but are distinguished from true climbers in two ways: A larger overall size (20'–30' tall is common), and a once-blooming habit. It should be noted that both climbing roses and rambling roses are not true vines such as ivy, clematis or wisteria; they lack the ability to cling to supports on their own, and must be manually trained and tied over structures such as arbors and pergolas. Examples: 'Blaze' (repeat-blooming climber), 'American Pillar' (once-blooming rambler).

English / David Austin

Although not officially recognized as a separate class of roses by any established rose authority, English (aka David Austin) roses are often set aside as such by consumers and retailers alike. Development started in the 1960s by David Austin of Shropshire, England, who wanted to rekindle interest in Old Garden Roses by hybridizing them with modern hybrid teas and floribundas. The idea was to create a new group of roses that featured blooms with old-fashioned shapes and fragrances, evocative of classic gallica, alba and damask roses, but with modern repeat-blooming characteristics and the larger modern color range as well. Austin mostly succeeded in his mission; his tribe of "English" roses, now numbering hundreds of varieties, has been warmly embraced by the gardening public and are widely available to consumers. David Austin roses are still actively developed, with new varieties released regularly. It should be noted that the typical winterhardiness and disease-resistance of the classic Old Garden Roses has largely been compromised in the process; many English roses are susceptible to the same disease problems that plague modern hybrid teas and floribundas, and many are not hardy north of USDA Zone 5. Examples: 'Mary Rose,' 'Graham Thomas', 'Tamora'.

Canadian Hardy Roses

Developed for the extreme weather conditions of Canadian winters, these roses were developed by Agriculture Canada at the Morden Research Station in Morden, Manitoba and the Experimental Farm in Ottawa (and later at L'Assomption, Quebec). These two main lines are called the Parkland series and the Explorer series. These programs have now been discontinued; however the remaining plant stock has been taken over by private breeders via the Canadian Artists series. Derived mostly from crosses of native Canadian species and more tender roses, these plants are extremely tolerant of cold weather, some down to -50F. A wide diversity of forms and colors were achieved. Examples include 'Morden Belle', 'Winnipeg Parks' and 'Cuthbert Grant'.

Other notable Canadian breeders include Georges Bugnet and Robert Erskine.

Landscape Roses

These are a modern classifation of rose developed mainly for mass amenity planting. They are collectively known as shrub roses. In the late 20th century, traditional hybrid tea and floribunda rose varieties fell out of favor amid gardeners and landscapers, as they are often labor- and chemical-intensive plants susceptible to myriad pest and disease problems. So-called "landscape" roses have thus been developed to fill the consumer desire for a garden rose that offers color, form and fragrance, but is also low maintenance and easy to care for. Most landscape roses having the following characteristics:

• Good disease resistance
• Lower growing habit, usually under 60 cm (24 in)
• Repeat flowering
• Disease and pest resistance
• Non suckering, growing on their own roots.

Principal parties involved in the breeding of new Landscape Roses varieties are: Werner Noak (Germany), Meidiland Roses (France), & Boot & Co. (Netherlands).

Propagation

Cuttings and grafts are necessary for true offspring. Seeds work but you won't know what you have until it blooms.

Pests and diseases

Main article: Pests and diseases of roses

Roses are subject to several diseases, such as rose rust (Phragmidium mucronatum), rose black spot, and powdery mildew. Fungal diseases in the Rose are best solved by a preventative fungicidal spray program rather than by trying to cure an infection after it emerges on the plant. After the disease is visible, its spread can be minimized through pruning and the use of fungicides, although the actual infection cannot be reversed. Certain rose varieties are considerably less susceptible than others to fungal diseases.

The main insect pest affecting roses is the aphid (greenfly), which sucks the sap and weakens the plant. (Ladybirds are a predator of aphids and should be encouraged in the rose garden.) The spraying with insecticide of roses is often recommended but should be done with care to minimize the loss of beneficial insects. Roses are also used as food plants by the larvae of some Lepidoptera (butterfly and moth) species; see list of Lepidoptera that feed on roses.

See also

• List of roses named after people
• Rose (color)

External links

• All-America Rose Selections, a non-profit association of rose growers and introducers dedicated to the introduction and promotion of exceptional roses