Roses That Challenge
Most people are doubtful that roses can be grown in cold climates such as the northern regions of North America. Barbara Rayment knows differently. Owner and operator of Birch Creek Nursery, just outside of Prince George in north central British Columbia, Canada, Barbara raises roses and puts them through the rigors of testing. She propagates some varieties, brings others in from half a dozen different wholesale growers in Canada and the United States, and also collects hard-to-find hardy specimens through specialty rose growers to test and perhaps use as breeding stock.
Surprisingly, despite some of the most difficult climatic extremes (Prince George is in the Canadian Zone 3) she has found well over a hundred varieties, which make the grade (Barbara’s rose list of recommended varieties is attached at the end of this article).Barbara’s test and display acre undergoes varied and challenging conditions. Summers in the region are sometimes warm and dry, and sometimes cool and wet. Rarely does this region see very hot weather. In winter there may be 10 feet of snow cover or perhaps no snow at all. Winters can be mild with temperatures dipping -25 Celsius (the locals consider this mild!), and sometimes they experience -45 Celsius for a straight three weeks in November!
Of course, there is definitely a limit as to how far north roses can thrive, but there are a few species roses hardy to zone 1. Many cultivars (cultivated varieties) are hardy without protection in Zone 3 (-34 to 40 Celsius) and a further few are hardy to Zone 2 (-40 to 46 Celsius). There are some roses may be grown in parts of Alaska, northern British Columbia, certain northern areas of the Prairies, Ontario, Quebec and throughout the Maritime Provinces. The climate classifications apply to the rest of the world as well.
Barbara Rayment’s strategy in choosing which roses to grow in her rigorous northern climate is based on a mix of testing and optimism. She selects rose varieties simply by culling the ones that don’t do well and keeping those that thrive. Only those roses growing on their own roots have been found to be successful. Grafted roses tend to rot off at the graft if they don’t die back entirely. Even under the worst conditions, own root roses will usually re-sprout from their roots if killed right back to ground level. Because so many zone ratings are inaccurate, Barbara tests many, which she would like to be hardy, as well as those likely to be with as many pleasant surprises as losses.
Which species and cultivars of roses have managed to avoid the culling process? According to Barbara, ..my core of really hardy roses is the Explorer series, of course. She adds, the Morden/Parkland series also perform well, although (because of their parentage) they can tend to die back in very hard winters. In this case, hard winters are defined as these with virtually no snow cover. I can over winter anything under 6 feet of snow cover, Barbara says, even at 45 celsius. Under these conditions most roses do not grow as large as they would in milder climates. Having a smaller sized plant is acceptable and definitely preferable to no plant at all.
Barbara also notes that roses of the Rugosa heritage are generally as hardy as one can get; Hansa being a good example of this type of rose. The 1929 Finnish ‘Polstjarnan’ (a rampant rambler also listed as ‘Polestar’) is a northern classic. Unfortunately hybrid teas and even most of the highly popular David Austin English Roses are not reliably hardy although there are a few examples of them being grown successfully in this area.
Barbara comments; I am finding that some of the R. spinosissima hybrids and R. kordesii hybrids (the latter being the foundation of some of Ottawa’s work) do well. R. nitida and R. acicularis hybrids (both of those species are native to North America) are very hardy. Sadly not all of these hardy hybrid roses are easy to locate in the market place. Barbara also adds, the work of Frank Skinner and George Bugnet has largely been overlooked (except for the faithful old ‘Therese Bugnet,’ which is a large blowsy lavender-pink rose).