All too often, rose catalogs use the word “hardy” to describe roses that are not capable of surviving the average northern winter without careful protection.
That is why so many gardeners decide that they cannot grow them. They buy roses that die in the winter, and the conclusion is that in their area, roses are impossible.
Hardy With Protection
Of course, hardiness is a relative term. Quality varies considerably with location. Do not accuse the rose grower of intentional misrepresentation when they describe some variety as hardy when it is only hardy in a northern locality under proper circumstances.
The phrase “hardy with protection” instead of the word “hardy” in such cases would ultimately increase the growth of roses in northern states. Surely a brief note on protecting roses would not discourage any rose lover from growing them and circumvent many a future disappointment.
The ability to withstand severe winter conditions depends on both internal and external factors. A rose bush is comparable to a hibernating animal that fattens up during the late summer in preparation for long winter sleep.
The leaves are the fattening agent of the plant. Therefore, to prevent severe winter injury or loss, make sure that the fall foliage is retained in good condition, as long as possible.
Related: Growing Roses In Cold Climates
The Conditions of The Rose Bush Wood
Another factor that influences the hardiness of a variety is the condition of the wood in the fall. If the autumn is dry and the cold approaches gradually, the chances of survival are higher than if there are heavy rainfall and warm days. Late summer feeding is also conducive to immature wood at the beginning of winter.
Early growth should be encouraged. Fertilizing, watering, heavy pruning, and cultivation stimulate growth. After July, blooms should be cut with short stems.
Fertilizer should be withheld. Watering and cultivation should be at a minimum. If the bed is mulched, both watering and cultivation are unnecessary.
Atmospheric conditions may aggravate or lessen the effect of cold as registered by the thermometer. A long cold spell is more dangerous than a short one, and continuous cold winds from the same direction are deadlier than “still” cold.
The Winter sun also causes considerable injury to the leaves. It is not safe to assume that the hardiness of a variety is to be measured by the average temperature of the area in which it is grown.
Snow Covering
Snow-covering plays a big part in winter protection. A variety not hardy in an area where snowfall is light could winter satisfactorily in a colder climate where heavy snows can be depended upon to cover the plant almost all winter.
If roses are planted at the side of a hedge, away from the direction of the wind, the snow will drift in and increase the depth of the covering.
Adequate drainage of the rose bed is also integral. Although roses demand a considerable amount of moisture, they will not thrive during the summer nor survive the winter in waterlogged soil.
Practically all popular but tender Hybrid Tea roses can be wintered successfully in any part of the United States if the foregoing facts are recognized and adequate winter protection is given.
Protecting Roses Using Coverings
The safe and easy method of survival is to cover each plant with a mound of the earth after a few touches of frost have ripened the wood.
The mounds, after they are frozen, may be covered with straw, leaves, corn stalks, or any other material that will shade them and prevent alternate thawing and freezing.
The height of the mound should be at least 6 inches but can be considerably higher if the ambition of the person applying it dictates. The greater the height, the better, for in many sections the canes will freeze back to the top.
The higher the mound, the greater the amount of wood retained. In our far northern states, it is advisable to figure on ten inches or even more.
Tender and semi-tender climbers may be laid on the ground and covered with any material holding them close to the earth, preventing them from being subjected to winter sun and winds. Some people have successfully wintered many tender climbers without loss of wood by covering them, on the ground, with roofing paper alone.
The Hardiness Of Hybrid Roses
The hardiness of a hybrid rose ranges between that of both its parents. It would be assumed that the older Hybrid Tea varieties would show no winter injury at a temperature of 1° degree Fahrenheit since one of their parents (the Hybrid Perpetual) is reasonably hardy at 5° degrees below zero. The other (the Tea rose) shows sonic injury at any temperature lower than 32° degrees Fahrenheit.
There are numerous exceptions to this rule. Original Hybrid Teas do show slight injury at 10° degrees Fahrenheit. In their efforts to obtain greater floriferousness and a wide range of colors, hybridists have added more Tea blood, and the more recent varieties show greater susceptibility to cold.
We might suppose that Hybrid Teas of the Pernetiana class would be harder than others since they were derived by crossing a Hybrid Perpetual with the Persian Yellow. In some cases this is true, but as a whole, they are even less hardy because the foliage is weak and very susceptible to disease.
Several members of the genus Rosa have been found growing happily near the Arctic circle. Their offspring may be able to withstand the severity of our winters without protection and have a high standard of blooming capacity.
We can at least hope that someday extreme hardiness and floriferousness will be combined. Until that day arrives, we must either protect our tender roses or plant only those that can survive without protection.
There are several roses in this latter group, a few having withstood a minimum of 20° below zero in my garden without protection or the benefit of snow cover. Detailed descriptions of most of them can be found in catalogs and rose books.
Old Time Hady Roses Worth The Search
The Rugosa and Hybrid Rugosa group as a whole is quite hardy and also recurrent blooming. The most interesting of these, in my opinion, is the Grootendorst roses which will give continuous bloom until late autumn if the carnation-like blossoms are clipped as they fade. Grootendorst Supreme, F.J. Grootendorst, and Pink Grootendorst are the varieties referred to.
Others that deserve consideration are Agnes, Amelie Gravereaux, Belle Poitevine, Blanc Double de Coubert, Conrad Ferdinand Meyer, Dr. E. M. Mills, Dr. Eekener (sometimes not too hardy), Hansa, George Will, Golden King, Nova Zembla, Rose a Parfum de l’Hay, Sarah Van Fleet, Schneezwerg, Sir. Thomas Lipton, Stella Polaris, Turkes Rugosa Samling, and Vanguard.
A few of these may show some injury during a severe winter, not being killed outright by low temperatures, and will “come back” and bloom the following summer.
Practically all of the Centifolias, Damasks, Albas, and Spinosissimas are sufficiently hardy, some blooming more than once during the season.
Harison’s Yellow, Rosa altaica, and most of the species roses are in the same category, but their one burst of bloom more than justifies the space they occupy.
Stanwell Perpetual, Karl Forster, and Mabelle Stearns are three old-time “must-haves” for the rose lover who wants to continue to bloom with a minimum of effort. All are recurrent blooming and require no winter protection.
Stanwell Perpetual is an old member of the Spinosissinm family that has retained its well-deserved popularity for generations. Karl Forster is a white rose that should be in every garden.
One variety, Mabelle Stearns, is the perfect rose for those who desire high-quality and well-colored pink blooms in large quantities.
Few Hybrid Teas can surpass it in attractiveness and are sufficiently able to survive, without protection, over the most time in the United States. What more can we ask of a rose?
FGR-1147 – R. Shepherd