Something Beautiful for Our Harsh Climate
Published in the Ottawa Citizen, July 2, 2005
It is a truism that Canada’s national character is rooted in the relationship between the people and the land. From crossing the Northwest Passage to driving the last spike to surviving both in fact and fiction, Canada’s history of blood, sweat and tears spilled on the crucible of geography has been widely celebrated.
Canada’s birthday weekend is a time for reflecting on such matters but if, like mine, the patch of geography in your back yard is in need of refurbishment and refinement, the challenges may seem no less daunting than those faced by Canada’s explorers and pioneers. The good news today is that the same toil and genius that’s taming Canada’s geography is also available to the backyard gardener, even one sufficiently ambitious to attempt cultivation of that most civilizing of horticultural wonders, the rose.
Southern British Columbia aside, heroic efforts have been necessary for a garden rose to survive the Canadian winter but thanks to the visionary work of the Research Branch of Agriculture Canada and the genius of many botanists, including Manitoba’s self taught Henry Marshall, the Explorer and Parkland roses are meeting this challenge.
With the establishment of several government run experimental farms, Canadian breeding and development of hardy roses has been underway since 1886. In Ottawa, in the 1960s, this resulted in the development of the “Explorer” series. From Rosa Martin Frobisher, to R.Alexander MacKenzie and R.David Thompson, among others, the vigour and durability of the Explorer rose are becoming legendary among rosarians. With a genetic base in the Japanese/Korean native Rosa rugosa, the Explorer rose is easily identified by its deeply veined and crinkled leaves. Larger Explorer roses are of German, kordesii, heritage. Both types survive not only a snow bound winter but also the disease producing heat and humidity of an Ottawa Valley summer.
The Ottawa rose program is now located at Saint-Jean-sur-Richelieu in Quebec but at Agriculture and Agri-Food Canada’s research centre at Morden in Manitoba, a similar tale has been in progress since 1915. Here Dr. Henry Marshall turned to the native Canadian Rosa arkansana for his source of hardiness. Ubiquitous in the prairie’s Parkland region, arkansana is a tetraploid which made it a perfect match for garden roses like hybrid teas, also tetraploids. With this connection in hand, it was only a matter of time before the Morden research facility would be producing a variety of roses each as distinct as the roses with which native arkansana has been hybridized. These range from the mini hybrid tea-like pink flowers of Morden Blush to the blood red Hope for Humanity named in honour of the 100th anniversary of the Canadian Red Cross.
“All the roses are grown outside, which means they are automatically selecting for hardiness,” says Dr. Campbell Davidson. Currently in Ottawa on secondment from his job as manager at AAFC Morden, Dr.Davidson continues, “Minus 42 is the record low temperature at Morden. Often there’s no snow for cover especially in November when temperatures can go as low as minus 30”. The result is a plant that tolerates dry summers and cold winters without special protection. It also produces recurrent blooms and even if it dies back in the winter, new growth leaps back into action the following spring. “It’s great feature is its survivability,” says local nursery operator Mark Dallas. “And I’ve never seen a speck of mildew on any Morden rose.”
If this sounds too good to be true, perhaps it is. “Our plant breeding techniques are trying to develop resistance to black spot,” says Davidson. “But here in Ottawa the pathogen is different - different pressures on it has forced it to adapt and become a different strain.”
Black spot is that treacherous bit of fungus that spreads from one leaf to surrounding leaves and soil. The yellow and black leaf falls, producing the familiar leggy look of infected roses which may eventually die. Finding good combining material out of the wide range that is available, is the key, says Davidson. “What are the characteristics that will result – scent, shape, disease resistance?”
If survival is both a biological and a national imperative, Parkland roses offer valuable material, not only for this weekend’s backyard gardener, but also to guide Canada’s future. Now if only some way can be found to deal with the Ottawa pathogen.
MARGRET KOPALA’s column on western perspectives appears every other week.