Growing Roses in Minnesota (Zone 3A)
By Patti Gates Gardener (Lecturer and Active Member of Master Gardeners)
I live in zone 3A in Minnesota where the average frost dates are May lst and the 2nd of October. We have had frost into the first week of June and seen its return on the 3rd of September. Minnesota’s weather is always a challenge to gardeners.
Last winter was unusually long and hard in Minnesota. There was record cold and snow in winter. Spring had record cold and flooding, and now June is hot and dry with below average rain. The majority of winter damage we saw in our rural setting was vole and rabbit damage as high up as 4 feet on the roses. A number of us have maintained the Rose Research Garden in Bunk Hills Park in Andover for the past seven years. The mainstays of our garden are the hardy shrub roses, while nibbled quite a bit, are on their own roots and have come back. We add 10-10-10 fertilizer in the spring and again after the first flush of bloom on the hardy roses. We stop dead-heading (removing spent blooms) on the 1 2nd of August. Since we want to harden off the rose canes, we do not add any Nitrogen fertilizer to any of our roses after this date. We do not spray our roses. We try to keep the garden friendly for beneficial insects including ladybug nymphs, lacewings, and adult ladybugs, bees and soldier beetles that pollinate. Research has shown that planting alyssum as a border around the beds will aid in the control of aphids on the roses.
Once Rugosa roses have leaves in the spring, they hate being sprayed for insects or fungi. The sunlight shines on tiny droplets of water on leaves and acts as a tiny lens and bums the foliage and the blooms die. Rugosas also are hardy under difficult conditions: high winds, salt sprays, and dry gardens. They do not need as much water as other roses and are resistant to black spot. ‘Hansa’ has clove scent and is the hardiest cultivar in the violet-red colored roses with double blooms that appear in June. ‘Jens Munk’ tends to attract aphids but they do not bother the bush. It has at least 50 buds and 50 flowers at one time. It continues to bloom into October, until the snow flies. ‘Therese Bugnet’ is another rose I enjoy. I like the red, nearly thomless canes and the fragrant, double soft pink repeat blooms.
Our Canadian Roses include ‘Champlain’, ‘Charles Albanel’, ‘David Thompson’, ‘John Franklin’, ‘Henry Hudson’, ‘Jens Munk’ ‘Martin Frobisher’, ‘William Baffm’, ‘Adelaide Hoodless’, ‘Cuthbert Grant’, and ‘Morden Centennial’.
Some other winter hardy roses in our gardens include ‘Agnes’, ‘Austrian Copper’, ‘Belle Poitivine’, ‘Carefree Beauty’, ‘F.J. Grootendorst’, ‘Hunter’, ‘Pink Grootendorst’, ‘Magnifica’ and ‘Sir Thomas Lipton’, ‘Pink Meidiland’ and ‘Pompon de Bourgogne’. ‘Nearly Wild’ is our hardy modem shrub rose, and Rosa Glauca (Rosa Rubrtfolia) our Species rose. The following also weathered the winter unscathed: ‘William Baffm’, ‘William Lobb’, ‘Elveshom’, ‘Topaz Jewel’, ‘Salet’, ‘Reine des Violettes’, ‘Mary Rose’, and ‘Abraham Darby’, which is my favorite English Rose with its full blooms and fruity fragrance that will perfume your whole house. Makes nice potpourri too!
Always buy roses on their own roots, as they will be more resistant to disease. You will find them to be hardier and will not lose them to cold weather or animal munching. Considering my knowledge of their performance here, I don’t recommend ‘Simplicity’ or ‘Flower Carpet’. They do not do well in our area. ‘Flower Carpet’ must be covered or protected to survive. We plan to add new roses to the gardens: ‘Hanson’s Yellow’, ‘Henri Martin’, ‘Ballerina’ and ‘Mossman’ are some we are considering.