YANKEE DISTRICT OF THE AMERICAN ROSE SOCIETY

 


Winterizing Woes

By Angelina Chute

 

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fter the severity of last year’s winter, so many of our members reported losing many, and in some cases, most of their roses. Now with winter looming ahead, everyone is wondering what is the best way to winterize their roses to avoid such losses.

Before following any advice found in rose books and gardening magazines, we need to ask ourselves where the author is from and what zone he is winterizing for. Advice for winterizing roses in Arizona or in the southern part of the United States won’t be of much help to us in New England. In addition, we also need to understand why we winterize, make sure our roses are ‘zone appropriate’ and are in the best of health before they have to endure the New England winter.

I have read several recent articles on winter protection, but was curious to see what techniques were used in the “good old days.” My curiosity brought me to old American Rose Society Annuals and The Home Garden Handbook on Roses that was published in the 1930’s. What I discovered was that the advice given in the 1930’s and 40’s is basically the same as that given today.

Most people think roses need winter protection to keep from freezing during the cold winter months. In our area this is not the goal. According to Frederick F. Rockwell’s book The Home Garden Handbooks: Roses, “. . . it is not the cold which causes winter injury to roses but the alternate freezing and thawing, bright winter sunshine and drying winds, and late frosts in the spring after the sap has begun to flow. Therefore, it is these conditions rather than cold which winter protection should provide against.”

Our goal in winterizing roses is to keep them dormant and protected from the freeze/thaw cycle. During the January “thaw” when temperatures may soar into the high thirties and forties we want to prevent the roses from thawing and then re-freezing a few days later when the temperature plummets. This constant thawing and re-freezing results in winterkill. When the rose bush is uncovered in the spring, black, dead canes are all that may be left.  Roses need to be kept dormant from the first cold of December through the last frost of April. How we decide to do this depends on where we live and even the micro-climate of our own personal rose gardens.

No method of winterizing will be successful if our roses are not healthy. Roses that barely survived the summer are not likely to survive the winter. Roses that have been well cared for during the growing season will be better able to withstand the hardship of winter. This means that roses should have been fed regularly and kept disease and fungus-free.  It should come as no surprise that roses recovering from black spot or roses that are scrawny and infested with other fungi are not going to survive the New England winter. Roses are like people in this respect. If we go into the cold winters run down and in poor health, we are more likely to get the flu and colds. Taking good care of your roses in the summer months is a key to having them survive during the winter no matter what method of winterizing is used. It is also imperative that roses in our Zone 6B be planted with the bud union several inches below the soil.

I have read some interesting descriptions of various methods of winterizing roses in zones colder than ours, and the amount of work each takes varies. The Minnesota Tip is one of the most remarkable and work intensive procedures I have read about. In this method the canes are tied together and a trench is dug in the rose bed right up to the base of the bush. The bush is partly dug up, gently pushed over to lie down in the trench and then buried with soil. The Minnesota Tip sounds like a very good method of winter protection in a place like . . . Minnesota. It also sounds like an incredible amount of work. Another method used in climates colder than ours is one I saw used in “La Roseaie,” the rose garden in the Montreal Botanical Garden. Tender rose bushes that need a lot of protection are covered with special thermal blankets that are laid over wooden frames built around the beds. This method is very successful in this zone which is equivalent to USDA Zone 4.

Luckily most of us don’t need to resort to blankets and the Minnesota Tip. Two possible alternatives are rose cones and col-lars. A rose cone is made of styrofoam and look like an upside down ice cream cone. (They al-ways reminded me of dunce hats.) These white, very unattractive cones are placed over the rose bush that has to be trimmed and/or have its canes tied to fit inside. They also need to be weighed down to keep from becoming air-borne and usually a hole is put in the top to provide ventilation. The aesthetic effect of this winterizing technique is not a pleasing one. Luckily this method is not as widely used now as it used to be. The use of rose “collars” is a fairly simple process of encircling the base of the rose bush with a material such as a wire screen or plastic and then filling in this area with leaves or mulch or compost.

In his 1930’s book, Rockwell states,  “. . . the simplest and most effective form of protection for garden or bush roses is hilling up the soil about the plants.”  This is the method of winter protection Mike and I use and recommend. It is not only fairly easy but also successful. Despite the harsh winter last year we lost only two roses. It’s important to keep in mind that our roses are “physically fit” going into the winter. We feed them on a regular schedule from May to September as well as keep them disease and fungus-free through a strict spraying program and make sure that they are well hydrated through the growing season.

Our garden of ninety bushes is winterized over the long Thanksgiving weekend which follows Rockwell’s advice that the hilling up “should not be carried out until just before the ground is likely to freeze hard.” The first step in our winterizing process is to trim tall canes that may be whipped around by winter winds. One of the most frequent questions we’re asked is how much do we prune in the fall. The answer is that we don’t prune our roses at all in the fall; we prune them in the spring. We expect and accept some dieback and winterkill in the long canes left on the bushes. Our focus is to protect the bud union. The second step is to hill up the base of the bush, to a height of between twelve and eighteen inches, with horse manure. If manure is not available, mulch, leaves, compost or seaweed can be used instead. Once we’ve hilled up our winterizing is done except for our potted roses. These Mike buries in our manure heap or wood chips pile in the back of the rose garden. We don’t spray our bushes with any oil nor do we remove all of the leaves. If Mike feels very ambitious, after Christmas he’ll collect the discarded Christmas trees in the neighborhood, cut the boughs off and lay them over the rose bushes. The boughs act as a good insulator and also add interest to the garden. When the time comes to uncover the roses in the spring, the manure is just moved away from the base of the rose bushes and remains in the rose bed. Black canes may show above the hilled up roses, but the canes protected by the hills of manure are green. Mike then prunes down until he can see the creamy pith of the cane. This past spring some of our hybrid teas were pruned to about four inches. It was hard to believe that they had grown into full sized rose bushes eight weeks later.

It is important not to remove the winter protection too early. In early April we may be anxious to see how our roses fared, but remember to wait until “the Forsythia blooms!” The blooming of forsythia bushes is nature’s way of telling us that the soil has warmed up sufficiently. But the forsythia does not bloom at the same time even in a state as small as Rhode Island. The forsythias may be blooming in Pawtucket, but not in our cool back yard in East Providence. So stifle the urge to uncover the roses too soon. Also, if you think your rose bush is dead, make sure it is really dead. A newly uncovered rose bush may look dead, but give it a few weeks to bask in the warmth of the spring days to see if there is any growth. We have shovel pruned a bush or two that we thought hadn’t made it, only to find that its roots were still alive and well.

Need more information on how to winterize? Just come to our November meeting and take part in a hands-on opportunity to winterize the roses in Roger Williams Park. And if winterizing woes are getting you down, just keep in mind the beautiful June blooms that make all the hard work worthwhile.

 (February 2004 Rhode Island Rose Review)

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