A Blast From The Past

Anyone familiar with my garden knows I am a fan of evergreen plants. That makes sense. I live in a gardening zone notorious for its lengthy off season. Not only are our winters long, but our early spring and late fall can also be cold and anything but green. So I grow yews, and arborvitae, and of course, boxwood. A landscape that has something to say all year round is a good landscape. I would say the signs of spring probably presented themselves seriously a week ago or so.  The maples in the tree lawn are dusted with their chartreuse blooms. The grass began greening up. The hydrangeas in the foreground of the picture about are just beginning to leaf out. My large concrete pots are more visually important now than they will be at any other time during the season. They are beautiful, just so. unplanted. But the front yard landscape at this moment is really all about the boxwood. It is green and robust in much the same way it has been all winter.

The boxwood is quick to shed its winter coloration, as are the arborvitae, yews, and the old spruce in the background of the above picture.  I never tire of any of the evergreens, as the weather from one event to the next changes their appearance. The surfaces of the evergreens shimmering with rain drops in the spring is as beautiful as those same surfaces hatted by leaves in the fall, and snow in the winter. They are a crucial part of my landscape.

The role they play is never easier to see than it is now.  I can walk between the pruned and leafless hydrangeas, and see what a prominent role they play in the landscape. And I can even more appreciate the longevity of that service. Most of my boxwood at least 15 years old.

But cultivating evergreens in very cold climates comes with a price. The street side of my boxwood paints a different picture.  Extremely cold and windy winters can damage them. It is important to water evergreens well before winter. Once the ground freezes, the roots will have no opportunity to absorb water again until spring. Needled evergreens present very little surface area to the elements. That structure helps them to naturally conserve moisture over the winter. Though boxwood leaves are small, they are much more broad and thin compared to evergreen needles.  Extremely cold and windy weather can can quickly desiccate the leaves. If you have ever had a cut boxwood wreath on your front door for the holidays, you are aware of how incredibly long cut boxwood branches stay green. The same is true for cut evergreen boughs, or Christmas trees. This damage I am seeing now occurred months ago. The return of the warmer weather is revealing the result of terribly cold weather we had the end of January.

The polar vortex which occurred in January of 2019 is again part of the conversation. The intense cold that gripped a significant portion of the northern midsection of the US set records for cold and wind chills in a number places. I do know what I was doing then. I stayed at home, and only let the dogs out for a few minutes at a time. It was the coldest recorded winter temperature event for Chicago in 25 years.

From Wikipedia   “In late January 2019, a severe cold wave caused by a weakened jet stream around the Arctic polar vortex[3] hit the Midwestern United States and Eastern Canada, killing at least 22 people.[1][2] It came after a winter storm brought up to 13 inches (33 cm) of snow in some regions from January 27–29, and brought the coldest temperatures in over 20 years to most locations in the affected region, including some all-time record lows.[1][4] In early February, the polar vortex moved west,[5] and became locked over Western Canada and the Western United States.[6] As a result, February 2019 was among the coldest and snowiest on record in these regions. In early March, the cold once again shifted east, breaking records in many areas.[7] In mid-March, the cold wave finally retreated, but combined with above-average temperatures, precipitation, and a deep snowpack, widespread flooding ensued in the Central US.” Yes, it was a vicious weather event.

The impact of that extremely cold weather is beginning to be seen. I was faint with surprise when I saw the entire top of this picea mucrunata was dead. If you look up the phrase  “top of my spruce is dead”, most articles cite winter winds and extreme cold first. I see no eveidence of disease or insect damage. Could the polar vortex be to blame?

Of course the time to think about safeguarding evergreens from winter damage is in the fall. I have never seen damage on the boxwood cultivar “Winter Gem”. I plant it extensively now. I rarely plant “Green Velvet” anymore, which is the cultivar I have at home. Thankfully it rarely gets any damage, as I live in a neighborhood where the wind is broken by multiple buildings that surround my landscape, and the sun is tempered by large trees. I have never seen winter damage on boxwood that has been sprayed to the dripping point with VaporGard in the fall. A dry day when the daytime temperature is above 50 produces optimum coverage. Later in the fall, a windbreak of burlap can help. I would have never thought to protect my spruce, but maybe I should. A last bit about the boxwood.  Given the extreme cold we have had in the past years, the price of boxwood has skyrocketed. Replacing my damaged boxwood will be very expensive. Hopefully I will remember this day come the fall.

On a positive note, the below freezing temperatures and snow forecast for this past weekend never materialized. I am pleased to report my magnolia stellata is still in full bloom.


  1. Robert A Beebe says

    Just a thought from here in SE Michigan:
    Covering my boxwoods for the winter, out where they are in the most exposed position, has worked very well. First, I tried burlap tenting but without much success. So, I constructed solid particle board panel boxes 8 feet long, painted them green, with 3 sides and a partial “roof”. They come off in the spring, and are designed with hinge joints so they fold up flat for storage over the summer. These shelters have been in use successfully for four years now in an area where I had typically lost some plants every winter. Anything larger than a clipped and controlled-height boxwood could, or course, be just too big for such a box.

  2. Gail Hayes says

    So sad to see the damage to your beautiful garden. I am reminded that Mother Nature can be both unforgiving and generous. Keep up your brilliant work and thanks for sharing the good and the awful!

  3. Anita Berlanga says

    Timely article, as I’m just preparing to have 3 mid-sized boxwood pulled out from the lamppost on our front lawn. All 3 were Winter-killed, the last one in this last Polar Vortex. I’ll do marigolds for the coming season. I can’t face the idea of replanting box right now….

    Deborah, a question: how do you keep your concrete planters from busting (we share extreme Winter temps and I’m always terrified to leave them filled)? I was laughing, imagining some poor soul having to try to empty those ginormous planters of yours!

    • Deborah Silver says

      Dear Anita, my planters are full of dirt over the winter. What you can’t see is that the planters are up on feet. The critical issue is to be sure water can drain through. Water that is trapped in the bottom of a container will expand as it turns to ice-and that expansion can break even concrete pots. best, Deborah

  4. Anything you can do for the boxwoods now?

    • Deborah Silver says

      Dear Maggie, I would wait and see. In 2014 I was certain a huge portion of my boxwood hedge was dead. 4 years later, you could not tell there was a problem. Anything that is obviously dead-meaning that if you scratch a branch, it is brown beneath the bark, can be trimmed off. And then wait to see what happens. best, Deborah

  5. Jeff Swantek says

    Excellent article. I am definitely adding yew hedges along with the boxwood ones. I loved reading of your fondness of Semrau Garden Center and the clematis Sho-Un. Worked their while I was in high school over 40 years ago now.

    • Deborah Silver says

      Dear Jeff, your letter is a real blast from the past. I shopped at Semrau’s with my Mom 50 years ago or better. Happy to hear you are still gardening. all the best, Deborah

  6. Chris Boggs says

    Dear Deborah,
    It was my pleasure to meet you and Milo yesterday at DGW! Thank you for graciously allowing me to attempt to “take a selfie” with you. My short arms are better left for planting! Your words inspire me and your hospitality yesterday confirmed the artistic, gentle soul you are.

    Wishing you many, many more years of digging in the dirt!

  7. Here in England we live in fear of the boxwood caterpillar moth which can destroy a hedge overnight. So you haven’t been affected yet in North America?

    • Deborah Silver says

      Dear Anne, I am not familiar with the boxwood caterpillar moth. But several places in Michigan have reported boxwood blight. One place on a plant-and another place on a cut boxwood wreath. We are all very afraid of it. best, Deborah

      • Richard Muciek says

        Dear Deborah, our boxwood got hit also and are very yellow. I haven’t looked at their insides to see if there is any green left. What do you recommend? It could be very expensive to replace them with smaller ones and prohibitively expensive for a similar size.
        Any way to save them? Your advice? What will you do with yours?

        • Deborah Silver says

          Dear Richard, you should look in to the interior of your boxwood. If it is green inside – meaning the stems, when you scratch the bark, are green underneath-and the interior leaves are green, then you have a classic case of sun, wind and cold burn. You can give each boxwood a haircut back to the green. Dead branches will snap when you bend them-live branches will bend. In my case, I also have major branches missing bark on the interior-I suspect rabbit damage. One for sure will need to be replaced. Others may grow out of it. Sometimes we did up a damaged shrub, and turn it around so the damaged portion faces the interior of the planting. I am not in a hurry to do anything drastic, yet, beyond trimming off obviously dead leaves and stems. good luck! best, Deborah

    • Chris Boggs says

      Dear Anne,
      Unfortunately box tree moth is here in the USA as well! Information is starting to be distributed. As with any other insect/disease, it will be a battle to control. Here is a link to a recent greenhouse publication

      There is a new boxwood introduction on the horizon which is being promoted as more blight resistant.
      Called NewGen
      Hoping that the box tree moth can be controlled here before we see the deviating effects that you have been experiencing the last few years.

      • Deborah Silver says

        Dear Chris, I have not seen any moths or blight. Just winter damage from extreme cold and winter winds. And vole and rabbit damage to stems. best, Deborah

  8. I’m wondering if the cold winter was helpful in killing pest larva? I’m looking for the bright side.

  9. A timely post and outstanding topic. I, too, have Winter damage on my rhododendrons. First time in 30 years, the leaves are brown, rolled up vertically and falling to the ground. I expect in a week or two I will have twigs and no leaves on about 60% of my rhododendrons. I will probably trim them back severely and hope for the best. Everything else on my property seems fine. I also like conifers and ornamental trees.

  10. Kitty Gibson says

    Deborah – Those are beautiful planters, with the faces, in front of your house. Have you thought of placing a large grapevine orb in them? I put bamboo or thin metal rods through the center of my pot to hold the orbs in place from strong winds. Also, I have covered some of my grapevine orbs with natural moss using a glue gun. This gives me some green color until my annuals get planted in the planters.

  11. Lisa at Greenbow says

    The vortex took my Silver Bell tree. It was a relatively newly planted tree. Only it’s second winter. So far I haven’t seen any other damage. I think it is always sad to see the winter damage on boxwoods such as yours. I hope it all grows back.

  12. Patrick Hall says

    Great article, thanks! Sorry about your damage!

  13. Diane Miller says

    Hello Debra,
    Your question from Anita reminded me of a program I helped develop at the garden center I retired from recently.
    We worked with frost proof pottery. But to add to the life of the containers, we placed liner pots in side the large heavy pots. These liner pots were heavy plastic, the kind large landscape plants come in. Clients could bring back the liner pots seasonally to be replanted. Some had multiple pot liner for multiple seasons as you so beautifully do.

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