Tuesday, April 7, 2015

Wintering Roses - The Canadian Way

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Because the earth bulges at the Equator and is flattened at the Poles, the halfway point between the Equator and the North Pole is actually 16.2 kilometres north of the 45th parallel. This means that the garden here is just about at that halfway point. It also means that we are roughly at the same latitude as Grenoble, Turin, Simferopol in Crimea, Xinjiang in China, Hokkaidō in Japan, Michigan and Wisconsin in the United States. However, our climate here in Ontario and that of the two northern states is, to say the least, very different from that of Grenoble or Turin. Only now is the last snow  melting as you can see below.






You might wonder what all this has to do with roses. Because our winters are so cold, rose bushes have to be especially protected. It means they have to be laid on the ground and weighed down, so they get well covered with snow in November and December. By the time the severe cold comes in  January and February, they should be cozily tucked in and protected from the -20 and the like because, when there is a good snow cover, the temperature at ground level, under the snow, is about 0 degrees Celsius, regardless of how cold it is above the snow.

Rose that spent the winter under a board (now pushed aside) covered with snow



This laying down has to be done for all tender climbers. In the following picture, you can see part of a Pyracantha that was sticking out of the snow when severe cold came.  Consequently this part has been killed. The bottom part of the same plant survived and is green.  Actually 90% of the plant is still under snow and alive.


Green part was under the snow during cold spells, top part was not and died


Now that the snow is finally melting and there is no further danger of very cold temperatures, these rose bushes can be raised from their wintry retreats and  reattached to the trellis. This is the time they get pruned in preparation for another growing season. The first pruning is simple: you remove all the parts that have died over the winter.  Nothing has died in the picture below.





If you are in a cold climate, having a lot of snow is actually a blessing.  Here, once the snow has fallen, it does not usually melt till spring. South of us, where winters are more temperate but still very cold, there often are warm spells and melting periods in the middle of winter. Then temperatures plunge down, the cold returns, and roses are caught unprotected and suffer a great deal of damage. We had some of that last year. The most frustrating damage is when a climbing rose gets frozen near the base and the rest of the cane is in perfect condition. The frozen part has the effect of girdling the plant, and you have to chop it all off. This year there does not seem to be any such damage.



36 comments:

  1. Wonderful post! I have wintered over a small bush the last two years by almost burying it in soil. I knew I had to keep the roots "warm" and it's worked fine. But last year I added a climbing trellis rose. I covered its base well in soil, but didn't give a thought to the growth strung out on the trellis. After clearing out the base soil this weekend, I'm not sure about the prognosis. If I save it, I know what to do. If I replace it, I'll know what to do. Thank you so much!

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    1. Joanne,
      With your nail, scrape a little patch of bark on your rose bush. If you see any green it is alive. Don't be too fast to throw it out if you don't see any green. Much of the exposed branches might be dead but the base still alive. If eventually it sprouts only from the root, then what is left is the plant your rose was grafted on (probably a dog rose).

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  2. We have much in common, including our latitudinal challenges. I am at 43N here in Southern Wisconsin--close to Toronto's latitude. We had a brutal winter last year, and a rather "normal" winter this year. So, it also depends on the jet stream pattern for a particular winter. You're right, though--snow cover here is definitely a blessing! I don't have any climbing roses, but the few shrub roses I have are pruned way back in the fall. They're hardy varieties that come back year after year. One is a hybrid created by my great-grandfather, who crossed a wild Minnesota rose with an English tea rose. The scent is incredibly sweet! But it is somewhat susceptible to thrips. I'm an organic gardener though, so Neem oil and insecticidal soap seem to help keep the thrips at bay. Love roses! Great post!

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    1. Brutal last year, normal this year is a good description.
      I don't spray either. Here the problem with roses is a small green caterpillar called rose slugs (sawflies). Chickadees eat some but I would need dozen more chickadees!
      It must be very rewarding to grow a rose hybridized by a great-grandfather!

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  3. Thank you for that interesting post!I had no idea that you could - or indeed, would - do that to roses. I think of them as being fully hardy, as I guess they are in our climate here in the UK. I never realised that you could use a blanket of snow to protect them in this way.

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    1. Actually, if we had the winter temperatures we do with no snow, we would lose a majority of our perennials. That is why for gardeners here a January thaw is much more worrisome than -30 with a good coat of snow.

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  4. I had no idea that roses weren' t hardy. How enterprising laying them along the ground to keep them snug under the snow.

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    1. It is a lot of work but it works! Some roses are quite hardy. Multiflora for instance will survive most of our winters with no protection. But tea, noisette and hybrid tea are hopeless. Some varieties developed in Canada and the US specifically for cold resistance are very tough.

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  5. Climate is influenced by many conditions.

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  6. I often write about alpines such as saxifrages and contrast the natural environment with variable cold, warmth, rain, snow, humidity at ground level here in the UK Winter. Certain high alpine plants are just as you describe covered by a blanket of snow in nature and grow there but not in England!
    Actually Alain I now remember you commented on my recent post that saxifrages do not do well for you - I am surprised. But then I believe you have also problems with wet soil

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    1. I think I need to have a serious look at their requirements. I used to have some saxifrage in too much shade and they did not do well. For the last few years they have been facing South in full sun in a trough. They probably do not like these extremes.

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  7. I remember my late brother talking about Canadian winters, he used to live near Montreal. Gardeners have to be inventive!

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    1. There are of course a few silver linings. Tomatoes for instance are very easy outside and so are many plants that need a fair bit of sunshine in summer.

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  8. I often think that the severe Winters you get in your part of the world would be quite an endurance test, and yet some of the best Summer displays I have seen happen to be in Canada.

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    1. It is a bit of an endurance test for gardeners but, as I said above, some plants like our climates! In the specific area where I garden, cypripedium parviflorum for instance grow profusely with no help.

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  9. Fascinating Alain, it makes perfect sense of course I actually wrote a few posts ago that many of my plants, even those with hairy leaves, would be better under a layer of snow for the winter, a lack of which is why we struggle so much with alpines in the UK.

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    1. The snow is a great help. I think what would most surprise a British gardener is how fast the transition is from winter to summer.

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  10. This is so interesting. I had no idea that anyone was laying down roses for winter. I have hidden the occasional Agapanthus crown under layers of leaves, which hardly compares with what you're having to do to protect plants. Next autumn, I will remember this post as I get my garden ready for winter. I have NOTHING to whinge about!

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    1. Most gardeners in Canada and the Northern US have to do something like this. Usually they put specially made Styrofoam cones or layers of burlap over their roses. There are whole families of roses that were bred especially to resits the cold which are mostly unknown in western Europe but are the most commonly seen varieties in places like Ontario and Wisconsin. The German Kordes roses are also cold resistant.

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  11. You do have to work hared to protect your plants - I can't imagine trying to lay down climbers as our climbing roses aren't very flexible. Would they cover up?

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    1. Actually, since you have to lay them down every fall, you could say they develop a 'hinge' at the base. Of course, once in a while you break a stem. Leaving them in place and covering them with burlap would work in a mild winter, but our winter are rarely mild. You can see the climate is changing - the last 2 winters were very cold but 2012 was the shortest and warmest winter I can remember.

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  12. Well, I never! Had any idea that you had to go to such extremes, that is, Alain. Worth it all in the end though. I've often wondered why so many gardens over there and elsewhere in the states (with conditions such as yours) can manage to have some plants thrive that fail in their first winter here but your post has made it all the more obvious now.
    Every day is a school day :)

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    1. It is funny how each place and even each winter is quite different!

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  13. I had no idea you would have to overwinter roses like that. We have some inherited old shrub roses and they seem to withstand anything you can throw at them. Someone ran their car off the road a year or so ago and trampled our bushes. the next summer they came back as good as ever, I was amazed.

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    1. There are some that are very tough like most of the rugosas. However the climbers on the whole are not so cold resistant. Some winters they would make it without protection but not most years.

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  14. Hello Alain, I had no idea you had to go to so much trouble to over winter roses like this. It must be a fair amount of very prickly work. I'm very lucky in that I can just leave the roses to over-winter as they are, no preparation needed. Quite a few of the roses I have will retain their leaves over winter too. It just goes to show how different the climate is.

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  15. I've often thought that gardening in a climate of extremes would have its advantages. A proper winter, not the dismal grey wet variety we have here, and a much better summer. Whenever I read Canadian blogs the sky always seems to be blue! You certainly have your work cut out though.

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    1. It is not much of an exaggeration to say that the coldest it is, the sunniest it is. The coldest large city in Canada is Winnipeg but it is also the sunniest.

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  16. I find that I always suffer less losses when there is a protective layer of snow all winter. It really does seem to insulate plants from extremes. Just this little bit south, I don't protect my rose canes, but quite frankly, I think I'd have less damage if I followed your methods.

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    1. If we limited ourselves to really cold hardy varieties, we would have less work to do. As you know, it is a question of chance. This last winter was very good for roses here.

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  17. How are you able to bend the stems without breaking them? I've heard of this method before. What an intelligent way to protect your plants.

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    1. You do break some stems. This spring I realized that I had broken a large stem of New Dawn. The canes seem to develop a hinge at the base!

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  18. HI Alain, it's good if you get snow reliably in Nov./Dec. but if not it's a different story. I'd be interested to learn about your experience with roses and which you find hardiest. Maybe you've done a post on that already and I missed it? I'll pop in later to check your answer. It would be great advice for people living in such a cold climate. When we lived in the Alps winters lasted many months but we still had lots of roses and they thrived like weeds but we still lost the odd one, sometimes even in fairly mild winters. Ramblers were a good bet though as well as species roses. Looking forward to seeing your spring garden :)

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    1. You are right, a post on the hardiest roses would be interesting. I will look into it. In the past, few roses could grow in our climate but now there are quite a few. I was surprised to read in a French blog that someone was growing Thérèse Bugnet - a zone 2 (!!) rose developed in Northern Alberta. However I see that it is recommended by David Austin which would explain why it is grown outside Canada.
      Where it is cold with no reliable snow cover, you have not only to lay them down but also cover them with soil! That is a lot of work!

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  19. Alain, you're so right! We have cold winters with periods of warmth and then temps drop down and roses and other tender plants get damage. Now I prefer to grow Canadian roses, I have some of them and do not protect them at all for wintering. Do you have many climbing roses? I've read that there are some climbing varieties of Canadian roses as well.

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    1. Nadezda, look at this post where I talked about various Canadian climbing roses (John Cabot, John Davis (no thorn), Prairie Dawn, etc.)
      http://rochefleuriegarden.blogspot.ca/2014/07/rose-in-cold-climate.html

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