How to Overwinter Tree Roses

Roses are among the most beloved plants.  Matchless for their variety of colors and fragrance and forms, roses have a beauty that makes their persnickety nature part of their charm.  Roses need special pruning and fertilizing and insect prevention, but they also need strict attention to their fall and winter care. (Please note update at the end 5.3.2013)

Last year, I took some photos as I was preparing to overwinter my rose.  My ‘Double Delight’ tree rose is even more demanding with regard to its care than bush roses I also grow in pots.

Here is how I overwinter my tree rose:

Step 1:  Cease fertilizing roses 2 months before overwintering.  The first killing frosts in my area are mid-October so an August 15th deadline gives two full months for my roses to wind down and become convinced that it’s really OK with me for them to go dormant for the winter.

Roses, for all their complicated care, have a strong desire to grow even into the frosts.  No fertilizer, no pruning, and full exposure to cold temperatures/frosts tell them that they need to rest now.  While they’re in their two-month cool down, I dig a trench in my compost pile (which is more like a pile of leaves than a true compost pile).  The trench will need to be big enough to accommodate the tree rose laying on its side and whatever other roses I’ve been growing in pots.

Step 2:  Once the hard frosts have hit a time or two, I can safely prune them.  The leaves and flowers often have a dull purplish tone to them showing that they have been exposed to sufficient cold.  Roses already know it’s time to shut down for the season, so when I prune them for the winter’s covering, they just accept it and don’t rebel against it by trying to grow some more.  They are obedient roses.  Tree roses get pruned differently than a bush rose so my photos will demonstrate their winter care.

All non-landscape roses have a “graft union” (place where the pretty rose variety was plugged into the sturdy root stock).  For bush roses, it is located at the ground level and this graft union can be covered with soil or mulch.  I’m particular to pine bark mini-nuggets because they still pour when frozen and stay put during the winter.  The added benefit is the way they become part of the spring/summer mulch when I wash them away from the graft union.

Tree roses are different.  A standard form or tree rose has a root zone, a tall stalk that’s part of the rootstock, and the graft union is at the top of the root stock.  Since the graft union is what needs protecting, covering the roots with mulch does no good whatsoever for preserving the graft union.

The knotty looking section with stems coming out is called the graft union.  With bush roses, I’m content to leave the canes about 12-18 inches long.  Not so with tree roses.  I clip them back to about 3 inches from the graft union.  Otherwise the new growth in the spring will be long and so heavy that the weak juncture will break off easily.  So I try to keep the spring growth compact.  It begins in the fall as I cut away the dead canes completely and the green canes get clipped to approximately 3 inches in length.  I use sharp pruning shears that have been treated with bleach so I don’t contaminate the rose for its winter rest.

 

Step 3:  Once it is pruned, it looks very naked, I know.  But it will have less to try to maintain through the winter.  It may sound strange, but plants stay alive through the winter even as they are dormant.  If you have a large plant to try to keep alive, it will expend more of its stored food trying to keep it all alive…and it may end up killing the whole plant in the process.

You’ll notice I removed all the leaves which–at this point–will only be a source of disease inoculum for next year.  Even so, there may be some organisms on the canes, so I usually do one last spray of insecticide before wrapping it up.

 

 

 

 

Step 4:  Wrapping the rose for winter storage (left).

While I could just bury the rose in its pot, I prefer to take it out of the pot so rain and melting snow can keep the root zone hydrated.  Both the roots and the graft union need to be protected and with a long stalk, it risks being broken in addition to frozen.  Therefore, I take the extra step of wrapping it in frost cloth.  Both air and water can permeate it, but the rose will stay substantially cleaner and will make it less attractive for mice than if it were just buried among all the leaves.  Furthermore, wrapping the whole rose in frost cloth helps to make its removal in the spring less likely to break anything, whether the stalk or the graft union/new buds.

 

Step 5: Cover the wrapped tree rose in the trench with leaves.  Of course, the trench I’ve already prepared in the back and the neatly wrapped rose don’t look too good in the photo with both roots and graft union ready to be covered.  Should the police wonder what I’m burying, we could always open it to reveal nothing but the rose inside.  Last year my son had a few laughs at my expense as we went out and buried it.  But, I got the last laugh this spring when I unearthed it.

 

 

Step 6:  In the early spring, I unearth my tree rose and place it in a sheltered spot.  If it’s too cold outside still, I’ll put it in the garage.  I don’t want to leave it in the compost pile and have the leaf buds begin to “break” in the dark.  But I also don’t want to have gone through significant effort to overwinter it only to have it zapped by a late winter cold snap.  Unearthing it while it’s still dormant will allow it to develop naturally as the weather improves.  I pot it up, water it, and as the daylengths increase and the buds swell and break, I begin to fertilize it again.

My “Double Delight” tree rose began to experience bud break soon after unearthing/repotting it and it produced blossoms that were absolutely stunning this year.  By way of note, the stalk will not get taller.  The height you buy it is the height the standard (stalk portion) will remain.  The growth will be in the canes that arise from the graft union.  Bush roses can be grown in pots and overwintered the same way or planted in the ground (in their frost-proof pots) for the winter.  Landscape roses such as “Carefree Wonder”, many rugosa roses, “The Fairy”, drift or “Knockout” roses do not need this special care since they are hardier and not grown as grafted plants.  If you love roses but hate the maintenance, these “own root roses” are good options to try.

But for those of us who desire tree roses, we don’t mind that they are higher maintenance plants.  These jewels among jewels of the garden are well worth the extra care they require.   There is something marvelous about a reward of such beauty after a long labor of love.  It’s kind of a nice reflection in nature of the same beauty and reward of the Christian life well-lived. 

 

==== Important update (5.3.2013) For the first time in the decade I’ve been overwintering my roses this way, this year my roses were eaten by voles (a type of mouse).  Each of them looked like they had been put in an electric pencil sharpener and gnawed to a point.  I am attempting to root them (since there was remaining root stock below the graft union).  I’m not sure how well that will work since the bark appears to have been stripped all the way to the cambial layer, but I’ll keep you updated.

(2013) So this year when I overwinter my roses, it will include using hardware cloth (wire mesh with 1/4″ holes) to keep the voles from breaking my heart again next year.   As I wrap them in hardware cloth, I’ll include photos of that too.

That was ineffective as the voles found their way in, so last winter (2016-2017) I kept it in the garage.  I watered it periodically with cold water and kept the lights on in the garage to provide a little heat on the coldest of nights.  The result was a resounding success.  Cutting it back just as shown in the earlier photos, I placed it outside after danger of frost (putting it on the front porch tucked next to the house, if frost threatens).  Here is how it turned out.  It will be spectacular when it blooms.  I also did some containerized bush roses that way and they’re every bit as ready to burst into bloom! 

 

Categories In the Garden, Inspiration | Tags: | Posted on October 22, 2012

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8 Comments

  1. by Patty Colón

    On January 19, 2015

    Hello,
    I bought my first tree rose last year before spring. I planted it in a container and it did great all summer long. Now it’s winter here in NYC and I brought it indoors, unheated basement hallway where I keep all my other plants. I cut it back and it kept growing new shoots, I kept cutting until no more grew. My concern is that, the canes I cut back are green but one is half yellow. The original canes are brown and have been like that ever since the I first potted it and pruned (when I first received the plant) I’m scared for her dying. Please HELP!!

  2. by seminarygal

    On January 20, 2015

    I understand how we develop attachments to our roses and want to do what’s best for them! I wouldn’t worry about the green canes which sound like it is just the more recent year’s growth. Is the half-yellow one, yellow near the tip or near the knotty part of the stalk called the graft union? If it’s near the tip, that’s pretty normal and you will cut it in the spring just into the good part where the yellow part meets the green or brown (green underneath the bark) parts. I’m wondering if your unheated hallway is cold enough to keep it completely dormant. If there’s lots of light and very cold, that’s not so much a problem as it seems like spring to the rose (or like it’s growing in a different zone with mild winters) and any shoots are being produced in response to day length which at this point is increasing. But if it’s dark and not cold enough to keep it dormant, it’s chewing through its food supply to try to continue growing pale green soft shoots that aren’t going to be productive.

    The main thing with dormancy is that we want roses to gradually decide to give it a rest for a chunk of the year and not come in and out of it. It’s kind of like a human waking up every 2 hours with a new baby’s crying vs. the kind of sleep you get when the baby sleeps through the night. We want roses to go completely dormant in cold climates like ours and to go into that period of rest without subjecting it to the killing point of cold.

    So here’s what I’d suggest, if you have a thermometer, take the temperature of the hallway in the early morning and in the late afternoon to get an idea of day and night temperatures and to think about how much light these plants receive. I’d stop pruning any shoots that arise since that brings out the fighter instinct in roses that makes them want to keep growing. If it’s not cold enough, try to find a place where the air temperature doesn’t go below 28 degrees F, but is less than 37 degrees. That will slow the rose metabolism down so that it won’t chew through its stored food during the rest of the winter. If it is cold enough, reduce the water to the barest minimum and try to keep it dormant. In the spring you will prune away anything that’s dead and that’s when you’ll deal with the half-yellow one. Make sense? Feel free to write back with questions or for clarification. Hopefully this helps.

  3. by cheryle kelly

    On May 8, 2016

    i have two rose tree’s that i planted last spring. they were beautiful all summer. i put leaves around them and wrapped them in burlap. my question is its middle of may and it just looks like brown branchs with thorns on them when does new growth start ? i have rose bush’s and new green shoots are coming on them. are these rose tree’s alive? thanks

  4. by seminarygal

    On May 8, 2016

    If your rose trees were in the garden upright and you’re in a colder zone, the graft union (where the pretty part grows as a knob out of the long stem/rootstock) may have frozen. It’s the graft union that needs protection even more than the roots. Many people dig halfway around their tree roses and then lay them horizontally before covering the whole thing with leaves &/or burlap. But, one way to tell if it’s dead or alive is to carefully scratch a tiny bit of the brown/greenish bark on a stem or two near the knotty graft union. If there’s green underneath, then it’s alive and I’d keep it humidified (like misting regularly, or with moist sheet moss or an old coco-liner shredded and moistened) to keep it from drying out while it sends forth buds. That’s actually the best way to handle bare root roses as well. My newest tree rose which arrived with bare roots is just now beginning to send out buds and I’m in zone 5. So there may be hope depending on your zone and how sheltered it might have been. I hope this helps and good luck! 🙂

  5. by Chris Thiessen

    On December 7, 2016

    I live in zone 6. We are expecting temps down to 8-9 degrees in a few days.

    I have a beautiful tree rose that I don’t want to lose. I have a small heated green house. Is it okay to put the tree rose in the greenhouse for the winter and treat it like any other plant or do roses NEED the dormant period?

    I can also wrap it and place it in a corner of our deck that is protected from the wind. I don’t know which is the best.

    Thank you for any assistance.
    Chris

  6. by seminarygal

    On December 7, 2016

    Hi Chris, thanks for your question. Technically roses don’t “have to” go dormant in order to bloom and be happy during the summer. But roses do it for survival. If they don’t go dormant and the temperature drops rapidly below freezing or jumps rapidly, it’s the wild changes in temperature that cause the plant to be stressed. Signs of stress would be cane death, disease, insects, or deformity of flowers. Much is dehydration related. If you’re talking 8-9 degrees Celsius that’s way different than 8-9 degrees F which would be enough to kill the root zone and the buds/graft union. If you have a small heated greenhouse with room to place it, I’d acclimate it to the greenhouse for the winter. Maybe you could snuggle it next to the side for a day or two to get it accustomed to being a bit warmer gradually instead of just plopping it from cold to hot. Once you’ve moved it, keep it there until you can gradually move it back outdoors. Remember, it’s the fluctuations that present the greatest problem. I’m overwintering mine in the garage this winter since our temps were mild until just last weekend. Still can’t bury it because it’s still blooming and never went dormant so it will spend the winter in the garage. Cold, some light, and I will water it periodically to make sure it doesn’t dehydrate, using cold water so I don’t shock it with temperature increases. The reason I’d avoid the corner of the deck is that sunlight can still heat up the environment, even through the burlap. Hope that helps. Good luck! 🙂

  7. by Jackie

    On December 21, 2017

    I had voles eat all the bark off the bottom branches of my Juliet cherry bush. The top of the bush subsequently died, but it was able to put forth new shoots from the base. I have learned that using Scoot is very effective for keeping mice away. It is a very bitter-tasting substance that you spray on the bottom stems. The mice will not eat bark that tastes horrible. Since I have been spraying Scoot on the bottom stems, the mice have never chewed my trees again. It is a white liquid concentrate. The white color does go away by the time the plant starts growing again so don’t worry about the white staying on your plants.

  8. by seminarygal

    On December 21, 2017

    Thank you, Jackie! I am afraid I’ve adopted the “Kill the nasty vermin!” approach. After they decided to nest in my car’s cabin air filter, I decided it was all out war. But yours is good advice to keep mice from girdling trees (chewing the bark all the way around and killing the trees.) With the roses, my major problem was that they devoured the entire root stock and much of the grafted part. Sad to say there was no coming back from that. So now, my tree roses live in my unheated garage, are quite happy, and there are locked and loaded mouse traps all around the perimeter of the garage to create a sense of fear and awe in the mouse population and make them move back to the woods and fields where they belong. 😀

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