The Truth About ‘Endless Summer’ Hydrangea

September 3, 2009 | By | Comments (9)

Anyone who planted ‘Endless Summer’ hydrangea in the last 5 years has a love-hate relationship with this plant. They either love the fact that they can now enjoy hydrangea blooms in their garden for the first time. Or they hate it because this vaunted plant never lived up to its hype.



You’re looking at a bloom on my ‘Endless Summer’ hydrangea. It opened up just this week. This marks the first time any of my three ‘Endless Summer’s have ever produced a bloom later than June. Not exactly what I was told to expect.

You remember the hype about ‘Endless Summer,’ don’t you? Here was a hydrangea that bloomed all summer long on both old and new growth. That “old and new” factor made a big difference. It meant that even if severe winter cold killed the plant (and its dormant flower buds) to the ground, it could still grow the next year and produce flowers. So Northerners so jealous of these gorgeous blue blossoms could finally enjoy the beauty that we Southerners know every June.

By and large, Northerners loved it. I scoured blogs and posts from gardeners all across the Upper Midwest and even Rocky Mountain states and many were wildly enthusiastic. They weren’t getting repeat blooms, mind you. They were thrilled at just seeing blooms at all.

Down South, the reviews were less positive. Most people I talked to had the pretty same experience as I. ‘Endless Summer’ bloomed beautifully on both old and new wood until the end of June. Then when it got hot and dry, the way it most always does down here, the plant entered suspended animation and never produced another blossom.

How could this be? Well, you have to know something about the history of the plant. ‘Endless Summer’ was developed by Minnesota’s Bailey Nurseries in collaboration with renowned woody plant guru, Michael Dirr. Walking through Bailey’s planting fields, Mike noticed an unusual specimen of Hydrangea macrophylla that bloomed not only on old growth, as most do, but on new growth too. And so ‘Endless Summer’ (the best marketing name for a plant ever bestowed) came to be. Bailey was just as shrewd about the pots for ‘Endless Summer.’ They wouldn’t be ugly black, like 99% of nursery pots are. No, they would be bright blue, the same color as the flowers. As soon as the first ‘Endless Summer’s arrived, they literally flew out of garden centers all over the country.

Now Mike and Bailey are smart people. I don’t think they’d put their names behind something that wouldn’t produce as advertised. So what exactly went wrong?

Well, let’s pretend you’re an ‘Endless Summer’ hydrangea growing in a pretty blue pot at Bailey Nurseries. Life is good. Every day, you get just the right amount of water and fertilizer to keep you in optimal condition. So you grow all through the summer, repeatedly producing new flowers.

Now you get planted in my yard in Alabama. Spring is nice, no freezing weather to nip you in the bud (what a great pun), and rainfall is plentiful. So you bloom like crazy from late May through June.

Then something awful happens. July arrives. It gets hot. Because you have lots of big leaves, you transpire a lot of moisture. You are always thirsty. But the mean, old Grump won’t water you every day. Why, sometimes when he gets home from work, you’re already wilting! Does he notice? No. He goes into the house and pops open a beer. Oh, very nice. Glad someone’s getting a drink!

You decide to get even. After two weeks of hot, dry weather, you decide to hibernate. Oh, you’ll keep your pretty green leaves all summer. But no matter what the Grump does from then on, you won’t bloom again. Nosiree. You’ve shut down for the summer.

So why did mine repeat bloom for the first time this summer? Credit our wacky weather. Instead of our usual summer drought, we’ve had steady rain all July and August. Plus, this has been the coolest summer in Alabama I can remember. Last evening, out on our deck, it was 72 degrees! The high for the day was 78. That’s at least 10-12 degrees below normal. So ‘Endless Summer’ didn’t go dormant. Thinking it was growing in Martha’s garden on Long Island, it finally produced a second round of blooms. Yippee!

So do you need Global Cooling to get repeat blooms on “Endless Summer’? Not necessarily. Try planting it in a container. People customarily water and feed plants in containers much more often than those in the ground. Under these conditions, ‘Endless Summer’ should think it’s right back at Bailey Nurseries in Minnesota and bloom throughout the summer.

One final note. ‘Endless Summer’ may not be the panacea Northerners had been hoping for after all. In Cold Climate Gardening, blogger Kathy Purdy in upstate New York reports a rather dismal performance due to late spring frosts that damage leaves and buds and cool summer temps that inhibit flower production. Oh well. Guess she’ll have to settle for those blue plastic hydrangea blooms from Wal-Mart after all.


  1. Jemmie

    Greetings, it’s 2015, zone 5 (southern Mivhigam living…..)

    And the wettestt summer! It’s like the Pacific Northwest. And my 32 Endlrss Summer hyd have jurassic blooms. I’m trying to etch this in my visual memory. Bowling ball size blooms.

    Note that we had a couple weeks of 10below zero temps this winter. so please don’t begrudge me this beauty
    And marvel at the tenacity.

    July 21, 2015 at 11:15 pm
  2. Roz Behan

    I live in Sugar Hill Georgia in my hy ranges are right by my rain barrel and they get plenty of water last year they didn’t bloom at all but I think that was the Awful winter and hot spring.

    but daddy anymore it will be the old fashioned ones because I think when I see them on other peoples gardens are much prettier a lot more flowers and they that blooms on them till fall

    April 21, 2015 at 3:10 pm
  3. Jean

    Nursery friend gave me one last year. It was blooming…now this year NO blooms nor did hers bloom either. Whats up with that? The Grump should be out early watering along with the rest of us crazies.

    September 4, 2009 at 9:50 am
  4. Grumpy Gardener aka His Excellency

    Grumpy answers:
    Ilona — The color of the flower depends on the pH of the soil. My soil is quite acid, so I get very blue flowers. In near neutral soil, the bloom is pale blue. In alkaline soil, the bloom turns pink.
    Florida Gardener — I’ve never seen a single ‘Endless Summer’ in south Florida. Guess there’s a good reason.
    Nancy — Pleased with your results. Has Tampa had plenty of rain this year?
    Beth — For the benefit of readers, Shelby County is very close to where the Grump lives (about a mile down the road). So your experience this year mirrors mine. Cut off the old blooms, keep the thing watered, and maybe with this crazy cool weather, you’ll get more blooms.

    September 4, 2009 at 7:46 am
  5. Beth @ Unskinny Boppy

    Mine is blooming too!! Right here in Shelby county. It’s been in the ground for going on four years, and this is the first year I remember it blooming this late. I actually made a mental note as I was pulling out of my driveway this morning that I needed to take a picture to document that it was reblooming.
    So, now’s the time when I should cut off all the old dried up blooms that are surrounding the new one, right?
    PS– you crack me up so much. I love reading this blog.

    September 3, 2009 at 10:47 pm
  6. Nancy

    I’ve had an Endless Summer in Tampa for 2 yrs. First yr. was in a pot and did ok, with blooms through the summer but not much growth. I put it in the ground this year in a place with morning shade. It has done well and is still blooming. I did notice that it wilts easily down here, but we’ve either had enought rain or I’ve watered enough to keep it blooming.

    September 3, 2009 at 10:13 pm
  7. FloridaGardener

    They sent three plants for me to test in South Florida. No go, they all died by June! They should have known better, I did.

    September 3, 2009 at 8:12 pm
  8. Ilona

    I love the photo- that is what it is supposed to look like:)
    This year I had the first bloom on hydrangea mariesii, but endless summer does well for me, just without the blue hue. I’ve noticed it in Columbus Ohio yards, and it seems to be doing well here generally.
    It is quite a wilter when the summer dries out, though.

    September 3, 2009 at 3:26 pm
  9. Kathy from Cold Climate Gardening

    Like I said, it’s a Goldilocks plant. It wants it not too hot, not too cold, not too wet, not too dry: j-u-u-u-ust right. The gardeners who love these plants the most live in the mythical average North American climate, and live to water and fertilize. It still reminds me of my grandma’s hydrangeas (she lived on Long Island, too) but one year practicality will win out over sentimentality, and ‘Endless Summer’ will enter the winter of its discontent.

    September 3, 2009 at 2:01 pm

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