In 1923, Cyril M. Clarke began testing peonies for cold hardiness on his Alberta property. He tested more than 2,000 varieties, writes Deborah Merriam for the Canadian Peony Society. Most are rarely grown now. The Central Experimental Farm in Ottawa has a peony history as well. William Saunders began testing peonies there in the 1890s. Today, Canadians are still growing peonies. According to Brian Jordan of the Prairie Peony Society, Chinese peonies (Paeonia lactiflora) are reliable performers.
Chinese Peonies with Single Flowers
Single-flowered Chinese peonies have one or two rows of petals and yellow centers, according to Brian Jordan. They are not as commonly grown as other flower forms but have an open simplicity. Jordan recommends the variety 'Krinkled White.' 'Pico' grows at the Central Experimental Farm. Both are white single varieties available at Canadian nurseries, such as La Pivoinerie D'Aoust Peony Nursery in Quebec. 'America' is a single red, available at Blossom Hill Nurseries in Ontario.
Jordan describes semi-double varieties as having several rows of petals with yellow centers Reiner Jakubowski, president of the Canadian Peony Society in 2002, writes that the better varieties should have a "distinct" center. He recommends 'Illini Belle,' a ruby-red semi-double, and 'Cytherea,' a pink variety. 'Firelight' is a pink variety growing at the Central Experimental Farm. All are available at Blossom Hill Nurseries in Ontario.
Doubles usually have no visible yellow centers, unless the flower is passing, according to Jordan.
Included in this category are bomb types, which have single petals surrounding a large double-type center. Jakubowski recommends 'Red Charm,' a double red that is in the collection at the Central Experimental Farm, and 'Louise Lossing,' a Canadian-bred white double tested by Cyril M. Clarke. Both are available at Blossom Hill.
Japanese and Anemone Types
Jakubowski describes Japanese peonies as resembling singles but with the centers (stamens) becoming more like petals. He recommends 'Westerner,' a white variety, and 'Sword Dance' in red. Both peonies are in the collection at the Central Experimental Farm. The anemone peonies have more petal formation at the centers. Jakubowski recommends the showy magenta 'Gay Paree' and 'Do Tell,' a light pink variety with pink centers. These varieties grow at the Central Experimental Farm and are available at Blossom Hill.
Hybrid peonies are the result of breeding between two species of peony and most are single or semi-doubles. 'Nosegay' is a single variety in pale pink and was in Cyril Clark's cold hardiness trials. 'Coral 'n Gold' is a single coral-colored hybrid peony of Canadian origin. Both are available at La Pivoinerie D'Auost. 'Claire De Lune,' a pale yellow, 'Requiem,' a white, and 'Moonrise,' a cream color, are part of the collection at the Central Experimental Farm and are available at Blossom Hill Nursery.
Tree peonies are actually shrubs, not trees, according to Jordan. They don't fare as well in the cold winters of Saskatchewan. They are better suited to the warmer parts of Canada such as British Columbia.
Intersectional hybrids are of both tree and herbaceous peony parentage. They disappear in the fall as herbaceous peonies do. Jordan recommends 'Golden Treasure,' a semi-double yellow variety, and the single yellow 'Bartzella.' Both are available at Blossom Hill Nursery.