2018 Winter Impact On Hydrangeas Part One

Time to report on 2018 winter impact on hydrangeas, part one. With this in mind in early May, I went out to my Zone 5 garden to see what winter had done to my hydrangeas that bloom on old wood. These are the big leaf hydrangeas (macrophylla) and mountain hydrangeas (serrata). I also checked on the oak leaf (quercifolias) and climbing (petiolaris) hydrangeas I have.


I held my breath, fearing the worst since we had a brutal 2 week spell of cold temperatures to close out 2017 and begin 2018 in southwest CT:
Table showing temps in winter 2017-2018

Table showing temps in winter 2017-2018


I was relieved to find that all my oak leaf and climbing hydrangeas had buds on them.


But then I had to muster the courage to inspect the troublemaker. Off I went to examine winter’s impact on hydrangeas that bloom on old and new wood. I have a variety of rebloomers (see list below). I also have some old wood macrophyllas like Lady In Red. Intentionally and unintentionally, my macrophyllas are scattered throughout various parts of my property with different levels of exposure to the elements. Here’s what I found.

As in prior years, the buds on one Lady In Red which blooms only on old wood were alive and well. This plant was protected from the prevailing weather by a neighbor’s house. The second Lady In Red was not so lucky: some tips and stems were clearly dead and showed no signs of life while other tips had live buds on them. Sadly, the first plant that came through winter with no scratches was later to suffer damage from a rare, freak tornado that tore into the plant. She is now badly damaged but still alive. The plan is to give her a severe cut back and reshaping after flowering to restore her.

Then I traversed the yard. Of my Endless Summer® , The Original collection, some had complete dieback, as shown in this photo (it is now regenerating from the base).

WINTER'S IMPACT ON BIG LEAF HYDRANGEAS SHOWS DIEBACK AND REGENERATIONfrom roots after complete winterkill of top growth.

2018 Winter Impact on this hydrangea killed all old stems. New growth is coming back from the base.

Some had partial tip dieback, some had partial stem dieback or full stem death. Below is a photo of one that had a little of everything. The fence helped a little. The same happened to most of the other rebloomers I have.
Winter's impact on hydrangeas kills some or all stems. New growth comes back from surviving stems.

Winter’s impact on this hydrangea killed some stems. New growth comes back from surviving stems.


BloomStruck® came through the best of all my Endless Summers® and the best of my entire collection of rebloomers. It is loaded with flowers at the tip of the stem on its prodigious new growth. The photo below shows what the plant looked like on May 4 after a very cool and gray April. The flowers are just starting (late June in CT) to color up.

Photo of Endless Summer BloomStruck® displaying full buds in early May

Endless Summer BloomStruck® displaying full buds in early May with no winter dieback.

This picture below shows a tip from another plant that you might have thought was dead in April or even mid-May and you might have cut it off. Nonetheless, by early June, it actually produced a flower bud. Consequently, the lesson is to be patient when it comes to cleaning up your plants in spring and wait to see “broccoli” before you cut those stems.
Photo of hydrangea flower emerging from brown tip

Bud emerging in June from what might have been thought to be a dead tip in April


*Other rebloomers I assessed:

  • Endless Summer® Blushing Bride, TwistnShout®
  • ‘David Ramsey’
  • Double Delights™ Wedding Gown, Perfection, and Star Gazer
  • Everlasting™ Revolution
  • Forever & Ever® Peppermint
  • Let’s Dance® Blue Jangles®
  • Midnight Duchess®
  • Mini Penny™
  • Nantucket Blue™
  • ‘Penny Mac’
  • Pink Shira™
  • Queen Of Pearls®



Inasmuch as I can’t control the weather, when I analyze which of my plants did what, I draw two major conclusions:

  •             First, the plants that did the best were those that enjoyed winter protection from one or more of several sitings: dry winter persistent foliage which might have been needled conifers like Alberta spruces or overhead junipers. They might have had oaks that held their foliage and helped block icy winter winds. In some cases, there was a garden shed or a house or fence which served as protection. Additionally, rhododendrons and azaleas protected some plants. Make them think they live in a warmer zone. 
  •             My second conclusion is that reblooming hydrangea macrophyllas are the only way to go. Where the tips of my plants died back, it is their reblooming capability that are producing the flowers along the stems. The magic of rebloomers is the answer for cold climate gardeners and can only enhance performance for gardeners everywhere else.


I’ll be back in a few days with PART TWO of my report. That one will detail how my hydrangea serratas, the mountain hydrangeas, made it through the winter.

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