Warm Roots, Happy Roses
How I handle winterization in northern New England
Lilias Bonechi | member, New England Rose Society, American Rose Society
March 2026
I was honored when NERS asked me to speak on a panel about winterization in 2024. I knew walking in that I had been gardening for the least amount of time out of the panelists. I found out that I was also in the coldest USDA Plant Hardiness Zone and did the least amount for winterization. It was a funny place to find myself when more is at stake in my Maine garden, but one thing I have discovered on my rose gardening journey is that growing roses is a very personal endeavor while also being so very communal. It is personal in that you end up doing what is best for your specific roses in your specific garden. It is communal in that we gardeners are forever learning from one another. My gardening tips come through my own experience as well as the advice from gardening friends; maybe you will recognize your advice to me in this article! With that in mind, I would like to share with you how I go through the winterization process with my 300+ roses in the ground in Maine in zone 5b.
Selecting cold-hardy roses
My winterization process starts when I am shopping for a rose. I want roses that can deal with a Maine winter, and there are a surprising amount that can. The first thing I look at is the hardiness zone. If the rose is suitable only to a zone warmer than the one I am in, I will pass that rose by. When I research information about a rose, the hardiness of the rose is reflected by a number. That number refers to the temperatures that should ensure the sustainability of the rose at its very coldest. Most roses will thrive in zones 7–9. Zones 6 and below are usually considered to be cold zones in the rose-growing world.
Planting budded vs. own-root roses
Once I have the rose at home, I take winter protection into consideration when I plant. I prefer own-root roses since they can die to the ground and come back in the spring, as long as the roots are still alive. If a budded, or grafted, rose dies to the ground it will most likely not come back. New growth comes from the bud union, and if the bud union freezes, it can kill off any potential new growth. When that happens, the rootstock, the rose to which the planted rose was grafted, is usually what pops up from the soil come spring. This is why people sometimes find unexpected Dr. Hueys in their garden! Some roses are happier budded, and I have quite a few budded roses in my garden. When it comes to budded roses, I just make sure to plant the bud union around 5 inches below the surface of the soil to protect it from freezing.
Encouraging healthy growth during the growing season
I prefer roses that are more disease resistant because it can get very humid during Maine summers, and the healthier a plant is going into winter, the more likely it is to survive. The German breeder Kordes prioritizes health in their breeding program, and so I recommend their roses if you live in a humid climate. Roses like Bliss, Dark Desire, Earth Angel, and Florentina, for example, are roses that require no disease control in my garden. They also require no winterization and thrive through winters in my garden with very little dieback. In general, I encourage health with soil amendments throughout the growing season. Anyone can get their soil tested to see which amendments would best suit their garden. I stop fertilizing at the end of August because that is 6 weeks before the first frost, and I stop deadheading at the end of September. During my last deadheading of the year, I cut back any extra long canes that could snap in the winter wind. In halting feeding and deadheading, I encourage the roses to head towards dormancy, though some of the stronger roses do not get the hint!
Deciding when to winterize
The roses in my garden were declared to be hardy to zone 5 by the vendor. That means, generally speaking, my roses should survive temperatures as low as -20 F to -10 F, so I allow them to go through the first couple of frosts unprotected until I see the first hard frost coming in the forecast. It is important not to start too early because you do not want to encourage rot through unfrozen, damp, compost. For the past two years I have been able to push the winterization process into the first few days of December.
Choosing a winterization method
Rose gardeners have quite a few options when it comes to winter protection. An extreme method is the Minnesota Tip method, which involves digging a trench next to the rose, loosening the roots a bit, tipping the plant into the trench, and covering it with dirt and leaves. Another method would be to build a cold frame for over the plants for wintertime. Purchasing a rose cone for each plant is also an option.
The method I prefer is the Hilling Method. It is a method used with vegetables in the growing season, and it is a relatively easy and effective way to winterize your roses. My ultimate goal is to protect the roots, especially from extreme fluctuations in temperature. Much of the plant can die from the cold, but as long as the roots are insulated, the rose should come back to its former size within a month or so from the start of growth. When I see the first hard frost on the horizon, I mound about 12 inches of compost around the base of each plant. Some of the smaller plants are totally covered by the compost hill that is 12 inches tall, but that is fine. I’ve seen chicken wire used as a way to keep the hill from collapsing, but I would rather it spread on the ground as much as it would like as long as the hill around the base of the plant remains 12 inches tall. This means the hill is often as much as 12 inches in diameter as well as tall. Once the hard frost comes, the hills usually stay literally frozen in place. I often get my compost delivered in bulk from a local nursery as they use compost from both land and sea, and roses especially love it.
Choosing which roses to winterize
I do not winterize all of my roses. At the end of 2025, out of 320 or so roses, I winterized about 70 of them with mounded compost. Most of the 70 are those that are on the smaller side, that haven’t had a chance to grow to their full potential. I also have three grafted hybrid teas that I will forever winterize. I am happy to provide winter protection to them year after year because they are roses that I especially love: Black Baccara, Buxom Beauty, and Fragrant Cloud. Hybrid teas are considered to be the least hardy of the roses, and these particular hybrid teas were confirmed hardy to zone 5 by the vendor, but I have seen other vendors rate them to zone 6, and even 7.
Spring reveal
In the spring, when I am quite certain no more hard frosts are coming and temperatures have balanced out, I pull the compost back from the base of each plant. I spread the compost around in my garden to be enjoyed by all the roses and other perennials who are waking up. While winterizing, I kept track of which roses I winterized. In spring I rate each surviving rose’s success through winter with a grade from 0–5, with 0 having dieback all the way to the ground and 5 having little to no dieback at all. Along with the Kordes roses I have already mentioned that have scored 5s without winterization, I have never winterized David Austin’s The Ancient Mariner, which I got as an own-root bare root in 2022, and the rose has scored a 5 each year as one of my very favorite and strongest roses. The Prince’s Trust, though a little less disease resistant, is a Harkness climbing rose that has also scored a 5 each year since I planted it as a 1 gallon own root in 2022, proving it to have a lot of winter hardiness, along with a lot of thorns! A third wonderful rose I have never winterized is Meilland’s Bolero, which has also scored a 5 each year since I got it as a band in 2022. All the time I saved on winterization I put into my excel spreadsheet of roses! I find it helps inform me as I make choices for my garden, especially winterization choices. A lot of what I do in my garden is for the years to come, which is why I consider gardening to be an especially hopeful endeavor.
I have had a hard frost sneak up on me one April after pulling the compost back from the roses, and my roses were fine. I did run out with a bucket to put over a newly-planted band just for that particular night! Flexibility is important when growing roses, as are patience and acceptance. You will lose a few roses here and there; everyone does. One of the beautiful things about roses is how resilient they are. As I type this, more than 2 feet of snow are covering my garden, and that is a good thing. It is the silver lining to getting so much snow, especially when the winter has been so cold. Snow offers insulation, and the roots of my roses are warm all the way under there. My goal is to one day let snow provide insulation to all my roses except for certain budded hybrid teas and occasional florist roses. I know it can be risky to not winterize every rose, but as my roses mature, they will be better able to bounce back from harsh winters. This is what I mean by the personal aspect to rose gardening—we do what is best for ourselves and our roses, always hoping for the best!
ABOUT THE AUTHOR
Lilias Bonechi grows roses in her zone 5b garden near Portland, Maine. She started her garden in 2019 by planting Carding Mill, Munstead Wood, and Coral Drift, none of which have required winterization! Follow her on Instagram to see more photos of her garden as well as her top ten roses of each growing season.