Endless Summer Hydrangea in two different climates

– Posted in: Hydrangeas, Plant info

Recently, Chris of Backyard Gardening Blog published a timeline in pictures, demonstrating the growth of his ‘Endless Summer’ hydrangeas. I found it very interesting to compare his photos with the few I took. You might want to have his post open in a separate tab of your browser so you can quickly flip back and forth to compare shrubs.

May 13, 2007. 'Endless Summer' is just getting started.

May 13, 2007. 'Endless Summer' is just getting started.

I didn’t take an early May photo this year, so we will have to assume that the hydrangea emerged from dormancy about the same time this year as it did in the photo above. As you can see, it is not even as far along as Chris’s May 1st photo, and Chris considered his hydrangeas behind in their growth at this point. Those are daylilies in the foreground.
June 4, 2007, a bit more than 3 weeks from the previous photo.

June 4, 2007, a bit more than 3 weeks from the previous photo.

I estimate the height at six inches in this June photo. They look to be at the same stage as the May 12th photo in Chris’s post.
June 25, 2008. Click to enlarge photo if necessary.

June 25, 2008. Click to enlarge photo if necessary.

Here you can see the first flower buds. The hydrangea is at a similar stage to Chris’s May 26th photo–a good month later than his.
July 6, 2008

July 6, 2008

The buds are further along, but still no blooms. Perhaps equivalent to the shrubs on the right in Chris’s June 22nd shot.
July 16, 2008

July 16, 2008

Okay, so now my very first blooms are starting to look like the shrubs on the left in Chris’s June 22nd shot. The blooms are starting to color up but haven’t gotten their peak color yet. At this point my ‘Endless Summer’ is at least 3.5 weeks behind his earliest blooming one.
July 27, 2008: fully colored up.

July 27, 2008: fully colored up.

I guess this photo above is pretty close to Chris’s July 6th photo, continuing the three week gap between his ‘Endless Summer’ hydrangeas and mine.
September 8, 2008.

September 8, 2008.

Unfortunately, I didn’t take any photos of the hydrangea in August. Now in early September the old blossoms are turning pink as they age. I can’t remember if they got as dark as Chris’s before our first frost on September 19th. But there was no second flush of bloom. You can see that the stems have elongated, partially obscuring the flowers. You have to part the branches to see the blooms well. But no new buds are visible.

Microclimates are important

Chris is in Zone 5. Theoretically I am, too, though not too long ago I would have said I was in Zone 4. I still have a Zone 4 growing season, with later spring frosts and earlier fall frosts. And Chris has one other advantage. Did you notice it? That stone wall behind his hydrangeas is providing a warmer microclimate by storing heat and radiating it back when the temperatures drop.

I have to say I was much happier with my ‘Endless Summer’ hydrangea this year than I was last year. I’m sure it improved its performance that I took care to mulch it with leaves last fall, and I didn’t pull them away from the plant until I was sure all danger of frost had passed. But I can also see that Chris gets more bloom from his ‘Endless Summer’ hydrangeas with the same amount of work.

I hope you found this comparison as informative as I did. A few extra weeks at each end of the growing season and a more favorable microclimate can make a significant difference in the performance of a plant. It’s a good thing to keep in mind when a fellow gardener rants–or raves–about a plant.

About the Author

Kathy Purdy is a colchicum evangelist, converting unsuspecting gardeners into colchicophiles. She would be delighted to speak to your group about colchicums or other gardening topics. Kathy’s been writing since 4th grade, gardening since high school, and blogging since 2002.

What differentiates a bulb from a perennial plant is that the nourishment for the flower is stored within the bulb itself.…There is something miraculous about the way that a little grenade of dried up tissue can explode into a complete flower.

~Monty Don in The Complete Gardener pp. 142

Comments on this entry are closed.

tedb November 7, 2008, 6:58 pm

Interestingly Endless Summers seemed to to better in 2007 then in 2008 here in Western Wisconsin. I also wait until late spring to try to keep as much old wood as possible. 07 was hotter and drier – maybe more wood ripened?

Blushing Bride, a cross by Michael Dirr between Endless Summer and Veitchii has been a much better bloomer for me, and I also prefer softer colors it has. It is even smaller then ES, maybe 30″ or so (bigger would be better in my garden, but more flowers is worth the short stature).

Kim November 6, 2008, 7:42 pm

Kathy, at least you got flowers! I don’t have Endless Summer, but I have 2 different types of macrophylla. The rabbits (or squirrels) ate them to the ground last winter, so all I got this year was foliage. One’s variegated, so foliage is OK. The other 3 need blooms and are safely ensconced under a net for the winter.

Mr. McGregor's Daughter November 5, 2008, 8:41 pm

I think all my flowering was old growth also. I protect my ‘Bailmer’ (Endless Summer) & my ‘Penny Mac.’ This was a great year for them both, but Penny starting blooming 2 weeks before Bailmer and stopped blooming before it also, although Penny had more blooms. My Bailmer started blooming on July 6.

Kathy Purdy November 5, 2008, 9:52 am

Chris, I didn’t know I was going to write this post at the beginning of the gardening season, so I had to scrounge around to get enough photos. The very first photo was from last year. This year I did NOT cut it back until I was sure all the buds had sprouted. Even last year I didn’t prune until after I saw new growth. And as I said in my post, I did protect it with leaves last winter.

IMHO, all the flowering I got this year was old growth. My frost-free season is a lot shorter than yours. I don’t think there is time for the new wood to bloom.

tina November 5, 2008, 2:01 am

I found this post very informative. You took a great of deal of time comparing the different stages and it is so neat how blogging can allow us to see the differences. Great job describing it all, though I did see the initial post. I love the Endless Summer in my garden. Also Blushing Bride is a winner.

TC November 5, 2008, 12:35 am

Mine is comin along. I don’t baby it, it’s in its second year. If it don’t survive my zone 5 winters, it’ll be replaced. I’m at a stage in my gardening life where I don’t grow things that require extra attention.

Chris November 4, 2008, 11:11 pm

Let me also say this. Most of my other hydrangeas from the macrophylla species (sp?) do not bloom, at all, for me. Only endless summer. I really only have one other variety from this species I like, with variegated foliage, it has never bloomed, but has nice foliage so I keep it.

Chris November 4, 2008, 11:09 pm

My stone wall faces north, so it actually doesn’t retain heat (no sun shines on it), and it is an unheated garage wall too, so it doesn’t leech household heat – but it does still offer some wind shelter of course.

It looks like you cut yours back all the way? I don’t. Typically my stems die back partway, but not all the way. So I cut back to where I see new growth (swelling buds) This can happen late so I wait to cut until like June or so.

The first flush of blooms I get is on old wood, not new wood, my new wood blooms come around the same time as yours. So again, your cutting back could count for most of it.

So here is my recommendation to you. Cover it this year, put a fence cage around wrap with burlap, and fill with leaves. Then, in the spring, don’t cut it back until you’re absolutely sure the stems are dead. Hydrangea stems look dead in winter and early spring but may still be alive.

My Mother, in upper zone 5 almost zone 4, maybe zone 4, had her Endless Summer bloom for the first this year, because she had protected it last winter (and also because she religiously turns on a motion activated sprinkler at night to keep the deer away).

Carol, May Dreams Gardens November 4, 2008, 9:08 pm

I was much happier with my ‘Endless Summer’ hydrangeas this year, too. I think it was due to all the rain we got in May, June, and July. But they still have never gotten as big as I’d hoped.