By: Fr. Gervase Degenhardt, firstname.lastname@example.org
To winterize or not to winterize, that is the question. Whether ‘tis nobler to suffer the slings and arrows of the vicissitudes of Old Man Winter or to take arms against his onslaughts and by opposing end them. Some rosarians might opine, “why this question? and why now? Hasn’t it been taken care of?” One would think that a subject so long with us, a subject so often dealt with before, a subject that, on the surface, seems to be so simple, would have been solved long before this, but in reality it hasn’t. So here we are, in a new millennium, and a rosarian is still asking that question while mutilating the poetry of the greatest bard of all time in, perhaps, the greatest soliloquy of all time. We beg forgiveness from both Shakespeare and Hamlet before we go back to that question.
It may sound surprising to many, but there is no phase of rose growing so rife with uncertainty as winter protection. In spite of all of the uncertainty though, autumn is the time to deal with the question. First of all, in almost all of our district, there is strong basis for claiming that no protection is needed. Nor do the problems and dangers that accompany winter protection outweigh all possible benefits which one would expect from protecting bushes from the cold. Secondly, there is no real agreement as to what actually kills the plant. Is it the cold, the drying action of the winter winds, the heaving action of the freezing and thawing of the soil? Is it the first too sharp frost or the last one just at the time the buds break? Thirdly, if winter protection is decided upon, there is scientific proof, backed by successful garden practice, that the material used for protecting the bushes should be a heat conducting material. And this material should be placed over the bud union which then conducts soil heat upward, or it should be a light dry insulating material which prevents the penetration of the cold. Fourthly, there is general agreement that winter protection should be put on after the cold weather is here to stay to avoid smothering the plant during the Indian Summer days of autumn. It should, then, be removed early in the spring to avoid premature growth under the cover which is chosen, that is too soft to stand exposure when the cover is eventually removed. This argument ignores two things: 1. the sharp October frosts which many have seen actually split rose canes, and 2. it runs counter to the belief that many rose growers have,that late spring frosts do the most damage. There is also a fifth area of controversy. How much of the plant is it desirous to protect? Just the bud union? Or, as much of the plant as possible? Many claim that with climbers, as much as possible. But with bush roses, there is merit in thinking that the removal of the rose canes by freezing or by pruning will stimulate the plant to produce basal breaks.
With all of this as a background, let us take up the question of the necessity of winter protection. Do not forget that, for the purposes of this article, I am talking about winter protection in the Penn-Jersey District only. One could hardly deny that in USDA Zones 2, 3, or 4 (maybe even, 5), winter protection is necessary except for the most winter hardy varieties. We could hardly do better, regarding this question, than by starting with what Dr.Cynthia Westcott has to say about it. Many knew her personally, and most know of her and her work and her writings. She claimed, in the first edition of her book Anyone Can Grow Roses that winter protection was a necessity. However, in her latest edition, she admitted that her own recent experiences and that of others in her area (New Jersey, New York) had convinced her it was not absolutely essential.
In her own inimitable-and often humorous-fashion (in an article written for the Pittsburgh Rose Society’s Newsletter), she states that she often found difficulty keeping gardeners “from whacking canes down to six inches or less in autumn and from piling on manure or leaves that would keep what was left of the canes too warm and moist over winter, with resultant cankers. The worst case of brown canker I ever saw was at a school of horticulture where, in a moderate climate, they had mounded the bushes with soil and then swaddled them with salt hay. I advised giving up all winter protection in that area and when I returned two years later there was almost no trace of canker. This control measure I term intelligent neglect.” Our famous plant doctor concluded this article with this advice: “I no longer believe in either a soil mound or a dormant spray, unless there is a severe case of rose scale. I do believe in summer spraying to make a strong bush to survive the winter. And I believe in loving your roses enough to know when they are healthy and in not disturbing them with unnecessary attention.”
In order to help us solve our question, we might ask: “Are there any scientific studies to help us determine whether winter protection is necessary or not?” There are but they only help to muddle the issue. In Chicago, results of overwintering records—8,500 of them during the fifties— seemed to prove Dr. Westcott’s later contention that winterizing was not essential. The best type of winter protection resulted in over twice the percentage of plants lost than when no protection at all was used. No one could deny that that seemed to bear out Miss Westcott’s conclusion. But, during the same years, in Cincinnati records were kept on 2,700 plants and the results clouded the issue, in fact, one could say the results were stunning, because they came to the opposite conclusion. Eight times as many unprotected plants were lost percentagewise as were protected plants. What could one say, except that “winter protection is necessary, maybe.”
Since Cincinnati clouded the issue, many rosarians in our district do not want to take the risk of no protection—and that is their prerogative. But the question then remains, “what materials to use?” Do we use the conductive materials such as earth, sand, slag or the insulating materials such as sawdust, peat moss, cocoa hulls? Generally, around the Pittsburgh area, the conductive materials have proved themselves effective when used as an 8-inch or so cover over the bud union. Many society members in this area have good success with it. But, the chief drawback is the amount of work involved, spring and fall, because of the hauling of the dirt.Where do you get the dirt? and where do you dispose of it? Because of all the work with the conductive materials, many have turned to the insulating ones, materials that can be mounded around the plant in winter and then spread out over the rose beds as a mulch in the summer. To quote a great rosarian originally from the Pittsburgh area, George Seymour, “the ever present danger here is the organic makeup of these materials which, when constantly wet and packed around rose canes, will tend to cause and/ or promote canker problems. Fine sawdust will definitely do this.” It seems to the present writer that the solution to this appears to be in using coarse materials which do not absorb or impede the flow of water.
The next question which we have to attack is that of the time of application and the time or removal of winter protection. Most certainly. I would favor late application and early removal. That would mean that one should not apply protection any earlier than Thanksgiving, but have it on at least by Christmas. Then one should have it off, and the bud union exposed to the weather, around the beginning of April. This seems to delay the new growth enough to avoid much of the damage from late freezes.
Experience seems to point out that to leave the winter protection on longer will then require special care for early basal breaks which started growing under the protecting material and were too advanced far too early. Experience also shows that those who use rose cones also have special problems in the spring. Since they insulate so well, growth starts early and bushes reach a size unable to be contained under the cone long before the danger of frost is past. All of these things lead us to conclude that winterizing still has much uncertainty surrounding it.
With all of this in mind, I would like to give you my experience in growing roses. I do not want to give the impression that my experience is everybody’s experience. Nor do I want to lead anyone to think that what I have done—and do—everyone, or anyone for that matter, should do. Nonetheless, this is my experience. As a young rosarian, beginning in the mid sixties, I was confused by all this. I had just moved to Herman, PA near Butler. It was definitely in USDA Zone 5, and in those days a cold 5. I rapidly became “hooked” on growing roses, and before long I had 538 plants. This was only supposed to be a hobby, and I needed to figure out what to do in order to save time. So circumstances of my full-time teaching job led me to adhere to the results of the Chicago experiments.
For 14 years, from 1965 to 1979, I grew these roses without ANY winter protection. I took care of them according to good rose-growing practices— watered, fertilized and sprayed. They went into winters healthy. And without any help from above they generally survived the winters in good shape. Sometimes I had to prune some of them very low, but they thrived. In the 14 years that I grew roses there, I lost hardly more than what you could count on two hands—and those, I’m not totally sure were lost due to the winter cold. My conclusion, most definitely, was that even if those dozen or so roses were lost to freeze-outs in those 14 years, the time saved made it certainly worth it. It seems to me that 14 years of success cannot be attributed to some sort of fluke or simply luck. I can only conclude that we generally make too much of winterization. I also feel that so much of what we do makes us feel good rather than do good for the roses. As a postscript, I would like to add that my experience was much the same while I lived in York, PA, USDA Zone 6, and a warm 6. And finally, my experience in Pittsburgh, USDA Zone 6, and a slightly colder 6, for the past 15 years is much the same. The general conclusion that I must make is that I simply do not (generally) winterize. The reason that I used the word ‘generally’ is that I have already used some winter protection on several roses which are considered extremely tender—’Color Magic’, for one.
Summarizing briefly, it is doubtful that winter protection of modern roses in our District will result in substantially greater percentages of bushes surviving. However, inasmuch as most of us are extremely apprehensive about taking any chances, we resort to some sort of winter protection applied in late November and removed just after the last hard frost. It is my opinion, that this practice at least makes us feel good, even if it does not help the roses at all. Mounding with dirt (if we do anything at all) is considered to be the most effective, but, at the same time, it’s about the most work. It is, thus, that alternative mulching materials and rose cones are used by many, realizing that there are some risks involved.
It would be nice to be able to end this article with a clear-cut answer, (which, of course, I feel like I should be able to do), but that is not to be. One needs to make one’s own decision. I do not want to sway anyone (OK, maybe someone who is looking for or needs less to do), but I will continue to do what I have done for many, many years, and that is, not winterize at all. If I were not convinced of all of this, and were not already doing all of this, I would now do it anyway because age is beginning to demand it. May all of you be blessed in whatever you decide to do
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