University of Vermont Extension 
Department of Plant and Soil Science

Anytime News Article
line
CHOOSING HARDY ROSES

Dr. Leonard Perry, Extension Professor
University of Vermont
 
With so many roses on the market, where does one begin in choosing plants that should survive in our northern gardens?  You might begin with named series of hardy roses, either ones from the last century or some of the more recent introductions.
           
Older series include the Buck and Brownell roses.  Dr. Griffith Buck bred roses in Iowa from the 1940's into the 1980's, most of which are hardy into zone 4 (-20 to -30 degrees F).  One of the better known is the deep pink 'Carefree Beauty'.  Performing well in Vermont has been 'Prairie Princess'-- light pink flowers with light fragrance resemble hybrid teas, and the plants are disease resistant.  Dr. Walter Brownell, an amateur breeder in Rhode Island, released his "Sub Zero" roses during the 1930's and 1940's.  These, such as the pink 'Nearly Wild', generally grow into zone 5 (-10 to -20 degrees F).  Most are based on one species (wichuriana), although you often find them equated to hardy hybrid teas.  Brownell roses tend to have resistance to blackspot, repeat blooms, and include pillar types.
           
A series from the Morden agriculture experiment station in Manitoba, Canada in the 1940's was the "Prairie" series, including 'Prairie Dawn', which has survived well in zone 5a (warmer part of zone 5) in Vermont.  These were based on native prairie species.  A later series from there, the "Parkland" series, has roses often with Morden in the name.  Examples from this Parkland series that have survived in Vermont zone 5a are 'Morden Ruby' and 'Morden Snowbeauty', as well as 'Prairie Joy'.
           
Another Canadian series, the "Explorer" series, was bred beginning in Ontario in 1961 by Dr. Felicitas Svejda, and with final breeding in Quebec in the 1990's.  These are generally considered among the hardiest rose series, are very disease resistant, and are named after famous Canadian explorers who, themselves, survived harsh winters.  Most show good disease resistance.  Many are cultivars from the Rugosa species (rugosa), or those from the newer German Kordes species (kordesii).
           
In Alberta, Canada in the 1940's and 1950's, horticulturist George Bugnet (said as boon-yay) was releasing his hybrids, named after family members.  These combine various species from Alberta, or often Rugosa roses, as well as a double wild Kamchitka rose from Russia.
           
The David Austin series of roses, from over 50 years of breeding in England, purport to combine the flowers and fragrance of old roses with vigor, disease resistance, and repeat blooms of modern roses.  These are often termed "romantic" roses, reflecting flowers of the past in appearance but flowers of today in their performance.  Most of these have proven very marginal and unreliably hardy in our Vermont zone 5a, a couple of the more hardy including 'Constance Spry' and 'Redoute'.
           
Similar "romantic" roses, but from the famous rose breeding company Meilland in France is the Romantica series, also listed as growing into zone 5. Most were released in the 1990's with European names, such as the yellow 'Michelangelo' or the dark red 'Traviata'.  The Sunblaze series of miniature roses, also bred by Meilland, is listed as growing into zone 5b (colder part of zone 5).
           
Their Meidiland and Carefree series were among the first to define a new category of "landscape roses"-- those for massing in landscapes that are generally low-growing, require little care, and have repeat blooming.  These often have shown winter injury or failure to survive in zone 5a in Vermont.  While most have Meidiland in their names, Bonica in 1982 was the first in this series and has pink, double flowers.  Use it as a shrub for borders or 2- to 3-foot high hedge.   It is worth mention as it often survives in zone 4, perhaps colder if good snow cover, and was voted the World's Favorite rose in 1997.
           
Another established rose firm in France, Roseraie Guillot, released their "romantic" Generosa series in the 1990's, but generally only hardy to warmer parts of zone 6 (not much below 0 degrees F), these are not suited for Vermont.  (This is the same firm that introduced the first hybrid tea rose, 'La France', in 1867.  This is considered the turning point, roses developed after then termed "modern".)
           
In the 1980's the Pavement series of landscape roses was bred by Karl Baum in Germany, "pavement" being a loose translation of the German for bedding.  These Rugosa shrub roses have strong fragrance, repeat bloom, large colorful fall hips, are hardy to zone 3, and are disease resistant.  They may be found by the German cultivar names, such as 'Rotes Meer' for 'Purple Pavement'.
          
 In the 1990's, from the Tesselaar firm in Australia, came the Flower Carpet series of ground cover or landscape roses.  More recent breeding in this series has added heat and humidity tolerance to long flowering and disease resistance.  They'll generally survive into zone 6,  perhaps zone 5 with reliable snow or other winter protection.
           
The Knock Out series has become one of the most popular and known landscape rose series, good in hedges or massed.  The Knock Out roses generally grow 3-to 4-feet high and wide, and may grow into zone 5 (although they are often listed for zone 4 and may grow there with protection).  Examples from this series are the original cherry red Knock Out, the light pink Blushing Knock Out, and the Double Pink Knock Out.  These are found in most retailers, all originally bred by William Radler of Wisconsin (reflected in the true cultivar names, such as 'Radrazz' for the commonly seen name of Knock Out).
           
Kordes of Germany is one of the best known rose breeding firms in the world, and has released many roses over the years.  Most grow into zone 6, some into warmer parts of zone 5.  They have released several "romantic" series such as the Fairy Tale roses with choices such as the double pink Cinderella or Pomponella, and the floribunda types in the Veranda series.  They have released several series of landscape roses including the compact and mounded Kolorscape roses, or the trailing Vigorosa roses.
           
One of Kordes most important contributions dates to 1952, and the introduction of a new species (kordesii).  While this species by itself made little impact, it did have impact in many breeding programs including the Explorer series from Canada, as with the cultivar 'Frontenac'.  Cultivars of this new species often are not hardy past zone 6, but those bred from this species often are more hardy, have good disease resistance, shiny foliage, and define the Kordesii rose class.
           
Among the most recent series are the Northern Accents and Easy Elegance roses from a Minnesota nursery.  These may grow into zone 5, a few having been grown in zone 4 in Vermont with poor results.  The Garden Treasures are relatively new miniature roses from California, listed as growing into zone 4b.  The relatively new Drift landscape roses are sold as groundcovers, reaching 1-2 feet high and 3-4 feet wide.  They're good massed, are good in the hot South, and are listed as growing into zone 5.
           
Many new individual roses or those in company brands continue to be released, particularly as either "romantic" or "landscape" roses.  Make sure to check their hardiness from multiple sources if buying online, or check with local nurseries on their recommendations.  You can find the most recent USDA hardiness zone map online (www.planthardiness.ars.usda.gov).



Return to Perry's Perennial Pages, Articles uvmext logo