Rose Classification Simplified

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With over 300 species and nearly 20,000 cultivars of roses to choose from, it’s easy to understand why it’s helpful to categorize them according to their most obvious traits. Source: T.Kiya, Wikipedia Commons

Confused about rose classification? Is that rose a hybrid tea or a floribunda? Or perhaps an old garden rose? If you’re lost, here are a few quick and easy pointers to point you in the right direction: just the right thing to bone up on before you head to the Rose Show!

Rose Classification

There is no single system of classification for garden roses. Pretty much every rose society has its own. In general, however, roses grown commercially these days are placed in one of the following categories:

1. WILD or SPECIES ROSES

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If the rose’s name is written in italics, it’s probably a species rose, like this Rosa glauca. Source: T.Kiya, Wikimedia Commons

• grow spontaneously in the wild
• single flowers, scented or not
• bloom once a year
• fruits (rose hips) often ornamental
• bear species names (Rosa blanda, Rosa glauca, etc.)
• variable hardiness (1 to 10, depending on the species)

2. OLD GARDEN ROSES or HERITAGE ROSES

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Old garden rose ‘Rosa Mundi’. Source: Libby norman, Wikimedia Commons

• date from before 1867 (1920 according to some definitions)
• generally small to medium-size flowers, often double
• often very fragrant
• most bloom only once a year
• many subcategories: gallica roses, damask roses, moss roses, etc.
• variable hardiness (4-9, depending on cultivar)

3. BUSH ROSES

Repeat-flowering roses, most developed after 1920. They were, through the 20th century, the most popular garden roses, but are now being replaced by the easier-to-grow shrub roses (see below). There are several categories:

A. Hybrid Tea Roses:

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Hybrid tea rose ‘Peace’. Source: Arashiyama, Wikimedia Commons

• large, double, reblooming flowers with high-centered buds
• one flower per stem, rarely more
• stiffly upright habit with sparse foliage, making a fairly unattractive plant
• height: usually 3-5 ft (1 to 1.5 m)
• usually grafted
• not very hardy (zone 8); winter protection needed in most climates

B. Grandiflora Roses:

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Grandiflora rose ‘Queen_Elizabeth’ Source: Captain-tucker, Wikimedia Commons

• essentially a hybrid tea with 3-5 flowers per stem
• all other characteristics like hybrid tea
• not very hardy (zone 8); winter protection needed in most climates

C. Floribunda Roses:
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Floribunda rose ‘Iceberg’. Source: pxhere.co

• smaller flowers, single or double, carried in large sprays (5 and above)
• stiff habit, but smaller, bushier and more attractive than hybrid tea
• height: around 3 feet (90 cm)
• usually grafted
• usually hardier than hybrid teas (usually zone 7, sometimes zone 6)

D. Polyantha Roses:

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Polyantha rose ‘The Fairy’. Source: rzysztof Ziarnek, Kenraiz, Wikimedia Commons

• significantly smaller flowers, borne in dense clusters
• abundant bloom most of the gardening season
• attractive habit, often spreading
• height: 30-60 cm
• usually grafted
• often fairly hardy (zones 4, 5 or 6)

E. Miniature Roses: 

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Miniature rose Mandarin Sunblaze®. Source: http://www.starrosesandplants.com

• small flowers, individual or clustered
• most rebloom
• height: usually between 6 and 24 inches (15-60 cm)
• grown on their own roots (not grafted)
• often fairly hardy (zone 4 or 5)
• can be used as houseplants if given a period of cold dormancy

4. SHRUB ROSES

(includes ground cover roses, landscape roses English roses [David Austin roses], etc.)

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Shrub rose ‘Henry Hudson’. Source: eaglelakenurseries.com

• various origins
• usually robust, informal habit creating a shrub effect
• single or repeat blooming
• variable height, usually more than 2 ft (60 cm)
• grown on their on own roots (not grafted)
• often offer good disease resistance
• excellent hardiness: up to zone 2 for some

5. CLIMBING ROSES

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Climbing rose ‘Blaze Improved’. Source: http://www.jacksonandperkins.com

• long flexible canes from 8 to 20 feet (2.5 to 6 m) in length
• can be trained and tied to arbors, trellises and pergolas
• all other characteristics are highly variable; flower size, abundance, appearance, rebloom, hardiness, etc.

6. TREE ROSES (ROSE STANDARDS)

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Tree roses. Source: Наталия19, Wikimedia Commons

• grafted onto on upright canes
• most are bush roses
• generally very tender (zone 7 or 8)
• often need to be buried in trenches for better winter survival in cold climates
• some are non-grafted, produced by selective pruning of shrub roses, and these are sometimes quite hardy (zone 5 or even 4)


There you go: the basic rose classifications you need to know. Good growing!20180423L T.Kiya, WC

2017: Year of the Rose

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Shrub rose Oso Easy@ ‘Italian Ice’. Photo: National Garden Bureau

Each year the National Garden Bureau, a non-profit organization promoting the pleasures of home gardening, selects one bulb, one annual, one edible plant and one perennial to celebrate in their Year of program. It’s a great way to discover a new plant or to learn a bit more about a plant you may already be growing.

Here is the last of the four plants honored in 2017, the rose.


A Reluctant Report

I must admit I found writing about the Year of the Rose a bit awkward.

First, to my mind, a rose is not a perennial, but a shrub, although I can grudgingly accept that the word “perennial” can be used to mean not just what a gardener accepts as a perennial, that is a “herbaceous perennial”, a non-woody plant that comes back year after year, but any plant that comes back year after year. So check that off.

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Me after a day of rose pruning.

However, the other factor is I’ve had a love-hate relationship with roses since my childhood. My father not only grew roses (hybrid teas and grandifloras), but worked as a gardener on estates with large rose gardens. As a result, my first summer job involved pruning roses and I simply was not yet, at 12 years old, dexterous enough to walk away from rose encounters unscathed. Those thorns just kept attacking me! I spent that summer looking like I’d just come out of battle with an enraged feline. I’m still amazed to this day I wasn’t blinded! As a result, en now I much prefer to admire other people’s roses than to grow my own.

And the third factor remains that, as a laidback gardener, I prefer to avoid plants that need a lot of attention. And although the resistance of roses to disease has made enormous progress since my childhood (back then, roses spent the summer so covered in rose dust – a combined insecticide/fungicide – that their leaves always had a bluish tinge… and this was considered normal and acceptable!), they remain persnickety plants, at least when it comes to insects, deadheading and, in many cases, winter protection. They’re still just too much work for me and the only roses I grow are ones that were given to me as gifts.

As a result, I’m writing this piece a bit reluctantly. If you love roses, there is lots of information to share about them and share I will. Just don’t expect me to grow the things!


The “Rose Report” for 2017

When I write about a plant, I usually put in my own grain of salt. In fact, I’m pretty heavy with the saltshaker. Here, though, most of the text was taken directly from the National Garden Association Web site with only a smidgen of modification. O.K., perhaps a bit more than a smidgen. Here goes:

There is no denying the popularity of roses. They are one of the most widely grown garden plants and indeed, the rose is the national flower of the United States, the United Kingdom and the Maldives and is popular as a state or provincial flower elsewhere.

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The redleaf rose (Rosa glauca, syn. R. rubrifolia) is one of the rare species roses that is commonly grown.

Roses (Rosa spp.) belong to the Rosaceae family and first appeared around 35 million years ago. There are more than 150 species of Roses, although only a few species are commonly grown. Instead, most gardeners grow hybrid roses.

People have been growing roses since the earliest recorded history. The oldest record is from China and dates back more than 7,000 years ago. Modern rose hybridization started in Western Europe in the 18th Century, and today there are more than 11,000 existing varieties of hybrid roses, with more being bred every year.

How Roses are Used

Although most gardeners think of roses mainly as garden plants, that’s only one aspect of their use. In fact, the rose industry is divided into 3 main areas: the fragrance industry, the fresh flower/florist industry and the garden rose industry.

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Field of roses in Grasse, France.

The fragrance industry uses mostly 2 species grown specifically for that purpose: the Gallic rose (R. gallica) and the damask rose (R. x damascena). The industry is concentrated on the Mediterranean basin where the climate is ideal for their culture. It takes 10,000 pounds of rose petals to make 1 liter of rose oil, one of the most widely used components in making perfumes.

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More than 1 billion stems of cut flower roses are produced annually.

The florist rose industry produces more than 1 billion stems a year in more than 30,000 acres of greenhouses worldwide. The industry started near important urban centers in Europe and North America in the late 19th Century, but has since moved to areas with climates better suited for their production. Columbia and Ecuador in South America, Kenya and Ethiopia in Africa and now China and India are the major producing areas.

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Painting of a rose in Empress Josephine’s garden, Malmaison, by Pierre-Jospeh Redouté circa 1798.

Last but not least, garden roses have been front and center in the garden since the Middle Ages when they were first widely grown for their medicinal qualities. The industry today is largely concentrated in developed countries (US, Europe, Japan and Australia) but they are increasingly grown in newly industrialized countries, especially in China.

Classes

There are many classes of roses. The most commonly grown are the following:

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‘Peace’, a hybrid tea, is the most widely sold rose in the world.

Hybrid Tea Roses are the classic, long stemmed varieties. They are not very hardy (about zone 8) and need winter protection in most climates. They are usually grafted.

Grandiflora Roses are similar to hybrid teas, but usually have several blooms per stem. Like the latter, they generally need winter protection beyond zone 8 and are generally grafted.

Floribunda Roses are multi-flowered plants with a more compact habit and smaller blooms. They tend to be a bit hardier: usually zone 7, sometimes zone 6. They too are usually sold grafted.

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Miniature roses are often grown in containers.

Miniature roses bear smaller flowers on smaller plants, from 6 to 24 inches (15-60 cm) in height. They often grown in containers as gifts and can be used as houseplants if you give them a long period of cold dormancy. They are grown on their own roots (not grafted) and tend to be fairly hardy (zone 4 or 5).

Climbing Roses bear long flexible canes from 8 to 20 feet (2.5 to 6 m) in height. Most are not natural climbers and have to be attached to their support. They don’t tend to be very hardy, though, and most have to be taken down and trenched for the winter in zones 8 and below. A few are hardy to zone 5 without any special attention. The very hardiest (to zone 3), such as ‘John Cabot’ and ‘John Davis’ of Agriculture Canada’s Explorer series, are actually shrub roses with extra-long canes that can be trained to climb.

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Oso Easy® ‘Cherry Pie’ is a shrub rose that can be used as a groundcover in sunny spots. Photo: National Garden Bureau

Shrub or Landscape Roses usually have a robust, informal habit creating a shrub effect. They tend to be hardy, sometimes even very hardy (to zone 2), usually grow on their own roots (not grafted) and modern varieties, at least, tend to more disease-resistant that other roses, all of which go a long way towards making them the easiest roses to grow.

Shrub roses have gone from a hodge-podge of varieties that did not fit any of the other categories and were rarely grown to become the main component of today’s garden rose industry. Popular series include Explorer roses, Meidiland roses, English roses (David Austin roses), Flower Carpet roses, Knock Out roses, Drift roses, OSO Easy roses and Carefree roses.

Today’s Garden Rose Industry

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Roses remain popular in garden centers around the world.

Today an estimated 35 million rose plants are sold each year in the US alone and it’s a market that is growing again after years of decline. About half of the total are shrub roses. Among the remaining classes, hybrid teas and grandifloras, so popular in the 20th century, still make up about 60% of the market, followed by floribundas (30%), climbers (15%) and miniature (5%). There is also a small but significant production of heirloom/heritage roses produced by boutique nurseries.

In North America, the main trends in new rose varieties are for low maintenance roses and roses with multiple uses. There is also a renewed interest in the old favorites, hybrid tea roses, but only if they are fragrant and more disease-resistant than traditional varieties.

Growing Roses

Thanks to serious breeding work over the last 40 years, today’s roses are much easier to grow than older varieties. They have been bred for vigor, disease resistance and controlled growth meaning much less work for the home gardener.

Full sun is a must for roses because, without 6 to 8 hours of full sun, you’ll have fewer flowers, long leggy (and weak) stems and a higher likelihood of disease. They don’t much like competition and should be planted well away from neighboring plants.

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Plant roses in sun in a rich, well-drained soil.

Plant them in rich, well-drained soil. They are quite tolerant of clay soils as long as drainage is reasonable.

Roses appreciate deep watering during dry spells. Try watering them with soaker hose or drip irrigation, as these methodskeep the soil moist and the leaves dry, the ideal situation for preventing roses diseases which tend to occur mostly on wet foliage.

For best bloom, apply a slow-release all-purpose organic fertilizer in early spring and follow up with a second application after the first flush of bloom. In mild climates, where roses bloom nearly year-round, a third application in late August may be wise.

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Once a very common disease, black spot is rarely seen on modern roses.

Thanks to careful breeding, the rose diseases that so bothered gardeners in the past, including black spot, rust and powdery mildew, are less and less frequent in modern roses, especially shrub roses, and symptoms are now often so reduced that many gardeners no longer feel the need to treat their roses to prevent disease.

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Rose chafer: one of the many insects that feed on roses.

Insect damage remains a problem and, depending on where you live, such scourges as rose chafers, sawflies, Japanese beetles, rose bud borers and rose slugs can be devastating. However, at least most modern shrub roses are tough enough to survive their attackers and will often start to again once they are under control. Rose gardeners should always be on alert for insect damage and ready to react when the first pests arrive. Early treatment is always the best way of controlling pests.

Winter protection is not necessary for shrub roses if you planted them in an appropriate zone. It is necessary for most other roses. Typically, hybrid teas, grandifloras and floribundas are pruned back harshly in late fall, soil is mounded around their base and they’re covered with a rose cone. Tender climbing roses need to be buried in a trench. Always remove the protection in late winter, before any new growth occurs. For more details on whether or not you need to protect roses, read No Winter Protection Needed for Hardy Roses.

Grafted roses tend to die after a few years, especially in colder climates, and the rootstock, a smaller-leaved, smaller flowered “wild” rose may take their place. Learn more about that in the article Dude, Who Switched My Rose Bush?.

Pruning Tips

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A bit of deadheading may be all the pruning you need to do.

Landscape roses don’t necessarily require much pruning, other than a bit of control to keep the plants compact. Many ground-cover roses don’t require pruning at all unless canes begin to reach into areas surrounding plantings. Alternatively, you can prune plants back annually by one-third to one-half to encourage fresh growth.

Using hedge shears, lightly prune plants to maintain size. This is best done in late winter or early spring, just before plants break dormancy. Also, trim lightly after a flush of blooms. Most modern roses are capable of reblooming and deadheading (removing faded flowers) helps encourage this.

A Rosy Future

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‘Crown Princess Margareta’, an English shrub rose.

Garden roses remain the number one garden plant in most countries and that trend will likely continue due to the unending advances in breeding which keep bringing superior genetics to the Queen of the Flowers.

Who knows, perhaps these continued improvements in ease of care (I’m banking on insect-resistant foliage as the next big thing in roses: keep your fingers crossed!) will finally convince me, the very reluctant, once-burned-twice-shy Laidback Gardener, to try roses again… but still, someone will have to do something about those nasty thorns!20170221aoso-easy-italian-ice-rose-pw

Bush Rose Hardiness: Little White Lies

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20140409OBe careful when you buy a bush rose, that is, a hybrid tea, a grandiflora or a floribunda rose (as opposed to a shrub rose). The label is not telling the truth about the plant’s hardiness: it’s a sort of horticultural little white lie. And if you don’t know this, you can find yourself, horticulturally speaking, screwed.

You’ll find these roses labelled as being adapted to hardiness zone 5, or maybe even hardiness zone 4, which seems to make them great choices for the northern half of the US and also southern Canada. In actual fact, though, they are no where near hardy in either zone, but most likely only to zone 7 or even 8. In other words, forget their surviving in Boston or Minneapolis: they’ll freeze to death in the winter in most areas north of the Mason-Dixon line. Why this blatant lie?

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Winter protection is required for most bush roses.

It occurs because nurseries assume you already know these roses are not hardy enough to survive on their own, that you are aware they need protection in almost any climate where prolonged winter temperatures below freezing are expected. Their zone 5 or zone 4 label is meant to give you an idea of what the plants can take if they are carefully protected for the winter. You’re expected to know that means, for example, abundant mounding if you garden in zone 6, a rose cone filled with mulch in zone 5 or even digging a trench and burying the plant for the winter if you’re in zone 4. And the same nurserymen assumes you know that a hard winter will probably kill these roses even with a good protection. Yes, they’re really that tender!

But this isn’t the 1950s when the average family had just moved from the farm to a suburban lot and brought lots of gardening experience with them. Those new suburban gardeners knew roses needed protection, plus they expected gardening to be hard work (that sort of a negative attitude towards gardening is slowly dissipating today), so didn’t think twice about the added trouble of plants needing winter protection.

Some 60 years later, that old gardening knowledge has often been lost. Yes, more people today are trying gardening than ever before, but many new gardeners never saw their parents or even grandparents garden. The whole thing is totally new to them. How are they supposed to guess that a zone 5 label means a plant is hardy in zone 5… unless it’s a bush rose? Even if you told them, it seems so ridiculous they probably wouldn’t believe you.

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Bush rose killed by the cold.

How many gardeners in colder climates lose their not-really-zone-5 bush roses each winter? I’ll bet that at least half are toast by spring. It’s unfair to expect beginning gardeners to know that, when it comes to bush roses and only bush roses, zone 5 really means zone 8. Yet if they have a bad experience gardening, they may gave up a hobby that should be fascinating, healthy and fun.  And that’s unfortunate for the gardening world… and the nursery with the lying label loses a client.

Truth in Advertising

Ideally, the hardiness zone given for any plant ought to be its real one. Of course, I fully understand the dilemma of a nursery owner: if he gives “zone 8” as the hardiness zone for a hybrid tea rose, he’ll scare away any gardeners from zone 7 down. I therefore suggest the following compromise. Why not label the plant as “zone 5 with winter protection”? That would make things much clearer. Even a beginner gardener would certainly understand he or she needs to do something to protect the plant from the cold and would, with luck, get information on how to do it from the garden center selling the plant.

Shrub Rose Labels Tell the Truth

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Hardy shrub rose ‘Winnipeg Parks’, zone 2.

Oddly, the same nurseries that lie about the hardiness of bush roses tell the truth about shrub roses! These roses are bigger, fuller plants and most are naturally more cold resistant (hardy) than the bush rose trio: hybrid teas, grandifloras and floribundas. Nurseries proudly list their true hardiness zone on the label: 2, 3, 4 or 5, depending on the cultivar. No winter protection is needed for these hardy roses as long as you plant them in their proper zone, or a warmer one. Thus, a shrub rose labelled “zone 2” can be grown in zone 2, but also in zones 3, 4, 5, 6, 7, 8 and 9 (most roses have a hard time with tropical climates: zones 10 and above). And a shrub rose bearing a “zone 5” label will grow, without protection, in zones 5, 6, 7, 8 and 9.

Make Life Easier

Larry paresseux 1 mg copyAs a laidback gardener, I strongly encourage northern gardeners at least to prefer hardy shrub roses to frost susceptible hybrid teas, grandifloras, and floribundas. After all, one of the  basic principles of laidback gardening is to stick to plants adapted to your climate. Not needing to protect a plant for the winter means less work not only in the autumn, when you cover or bury the plant, but also in spring when you remove the protection. So go with shrub roses: they’re much easier to grow!

Laidback Gardener Tip of the Day

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A Rose Hedge? Why Not!

octobre 21If you have no major problems with the roses in your area, such as rose chafers and Japanese beetles, roses make just as good a hedge than any other shrub. They even have the advantage, thanks to their spines, of making an excellent defensive hedge that neither thieves nor most animals would dare try to to cross. On the down side, they can only really be used as an informal hedge (a hedge that is not pruned into a geometric shape and is allowed to grow more or less naturally). If you pruned a rose bush into a typical rectangular hedge shape, you’d end up removing most of the flower buds!

Obviously you need to use a rose that is dense enough to make a good hedge and one that is highly disease resistant. Personally, I prefer modern roses as a hedge as they rebloom, but many of the old roses do make nice hedge plants if their brief blooming season isn’t a problem for you.

In cold climates, you’ll need to choose extra hardy roses, such as rugosa roses or those from the different Canadian series (Parkland roses, Explorer roses, Canadian Artist roses, etc.). Many German roses, especially the kordesii types, are also very hardy and make good hedges. English roses (David Austin hybrids) are moderately hardy (zones 5 or 6 and above) and many make excellent hedges.

All the varieties mentioned so far are considered “shrub roses” and indeed, they do tend to make the best hedges. Many of the bush roses (hybrid teas, grandifloras, floribundas, etc.) lack the dense growth habit a hedge rose needs, plus their limited hardiness (they tend to suffer severely in zones colder than zone 7 unless you cover them for the winter) is a problem for many gardeners. Polyantha roses are an exception. They’re considered bush roses and yet many of them, like ‘Cecile Brunner’ and ‘The Fairy’ make excellent hedges and are very hardy.

Among the other roses that do not usually make good hedges are ground cover roses (too low) and climbing roses (too arched and too bare at the base). Some of the taller landscape roses will however make a very acceptable low hedge.

So, think it over: many a rose hedge is just what you were looking for!

Laidback Gardener Tip of the Day

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Roses without Problems?

août 6Roses have such a reputation for playing the diva that many gardeners expect to have to prune, spray, clean and protect them in the winter just to keep them alive. But it’s not always true that roses are difficult to grow. Yes, there are capricious roses demanding constant attention and others that are insect and disease prone. As a laidback gardener, you should avoid those like the plague! Search instead for “easy-to-grow” roses and ones that are solidly hard in your area.

Most hybrid tea roses and grandifloras are in full diva mode and should be avoided. All climbing roses need to be fixed to their support, an extra step I find takes them beyond the “easy care” label: remember, you’re dealing with serious thorns here! Most floribunda roses are iffy too, although there are a few tough one. In other categories, though, there are roses that most laidback gardeners would find quite acceptable.

Shrub roses, groundcover roses and miniature roses are good choices in cold climates, as most are hardy to zone 5 or 4 and sometimes even zone 3. And among them are many that are also very resistant to diseases, although not always insects.

But the lesson to be learned here is to do your research before you buy a rose. Is it hardy in your area… without winter protection? Is it resistant to insects and diseases? You’d be surprised how many roses that fit precisely that definition.