Click on the photo for a list of plants

I’ve been growing two varieties of H. arborescens: ‘Abetwo’, which has the trade name Incrediball®, and ‘NCHA1′, which has the trade name Invincibelle® Spirit. I think both of them are far better choices for a cold climate garden than any macrophylla.

Invincibelle Spirit

When I first saw photos of Invincibelle Spirit, I wasn’t sure I liked the color, but I’ve found it much more pleasing “in real life.”

Invincibelle Spirit fits in well with other plants in a border

Invincibelle Spirit Hydrangea and Black Negligee actaea

Incrediball

Perhaps you’ve seen this image of the world’s largest hydrangea blooms?

Incrediball hydrangea. Photo courtesy Proven Winners

Incrediball's flowers are in scale with the rest of the shrub

The one weird thing about Incrediball is all the flowers are blooming beneath the leaves.

The blossoms are hiding underneath the leaves.

We’ve spent a lot of time fussing and fretting over that other hydrangea, but I thought it was time to highlight a few hydrangeas that earn their keep without being catered to. How about you?

Proven Winners sent me Invincibelle Spirit and Incrediball to trial in my garden.

I hate the plants that can survive a cold winter but can’t take a hard spring frost. It is so aggravating! The problem is they emerge too early from dormancy for their own good. I’m talking about:

• 

  April 29, 2006. Endless Summer hydrangea literally nipped in the bud.

  ‘Endless Summer’ hydrangea. It will get through a USDA Zone 4 winter but break into leaf long before the last spring frost. Which would be fine if those leaves could take a frost. But they can’t. I keep this shrub around for sentimental reasons. It reminds me of my grandma’s blue hydrangea–which was dead hardy for her on Long Island. I have learned if I bury it in leaves in the fall and leave them on until June, it will fine.
• 

  One night at 27F does it in.

  Arisaema amurense. There are very few arisaemas hardy to USDA Zone 4. This arisaema, native to the Amur River valley, is supposed to be one of them, though other sites say Zone 5. Unfortunately it emerges from its winter dormancy in May, when we still have frost. Frost makes it lay down and die a premature death. It’s not pretty and it makes me want to cry. And that’s not pretty, either.
• 

  Native-born but can't deal with spring frost

  Arisaema triphyllum. I know it’s a native, you know it’s a native, but just try telling that to Jack. Our native Jack-in-the-pulpit can’t take the frost any better than his Asian cousin. How the heck did it survive all these years? Perhaps provenance makes a difference. This guy came from a relative living in the Hudson Valley near Albany. I really didn’t think our climates were that different, but maybe little things mean a lot.

Can’t Live With ‘Em or Without ‘Em

By now you have probably guessed that I don’t really hate these plants or I would have let them go to their eternal composted rest before now. Really I love them; I just hate their little sissy ways and how they make me work to keep them alive. I really thought it was going to get colder than 27F (-3C) last night or I would have made the effort to cover them. It might–might–have gotten them through. Another two degrees colder and nothing would have saved them, so I didn’t bother.

Why bother, indeed? I’m either hard-headed or soft-hearted. I keep telling myself each year that this year’s weather was an anomaly, that if I just help these plants pull through and build up strength, eventually they’ll be able to deal with a weird spring or two without my help. Yeah, right.

How about you? Are there plants in your garden that make you pull your hair out, but you just can’t part with?

Every day I take a walk around my garden, and check my ‘Endless Summer’ hydrangea for buds.

I don't see any flowers, do you?

Wait! Do I see a flash of blue?

There's a flower in there!

Peek-a-boo!

Almost exactly a year ago, my ‘Endless Summer’ hydrangea was blooming. This year, as you can see above, it doesn’t even have buds.

What Went Wrong?

Okay, I forgot to feed it. Does it completely fail to make buds without fertilizer? I think not. It may not flower as profusely, and the blooms may not be as big, but no flowers at all?

The weather was not to its liking. There was that late May freeze. Yes, I covered it, but still. Other covered plants showed visible damage. Perhaps the hydrangea suffered damage that I couldn’t see, that killed the flower buds. Certainly the smaller hydrangea nearby got hit. It never recovered, either.

And the weather is still not to its liking. I think Hydrangea macrophylla likes more heat to its summer. We’ve scarcely hit 80F the whole summer. Not that I, personally, am complaining.

What’s Eating Them?

Are these critters causing those spots?

Some of the damage is from snails, I bet.

You can click on any of the captioned images for a closer look. Maybe you can tell me what's afflicting this plant.

I finally uncovered my ‘Endless Summer’ and ‘Forever&Ever’ hydrangeas. I had discovered that dumping a bunch of dry leaves over them in the fall was sufficient to protect them from the erratic spring freezes that we have. The old branches help hold the mulch in place, and I cut them down in the spring when I remove the mulch. You can see a few of the old branches in the photo above.

We have had frost in the first week of June in other years, and even though none was predicted for this week, well, we’ve had frost before when none was predicted. I’d rather uncover them a week later rather than have all their new growth blackened after weeks of waiting. That’s a certain way to lose a season’s bloom.

You can see the small, pale leaves that have been hiding under the mulch until now.

This ‘Endless Summer’ now has some size to it. I had two very small trial shrubs, and when we had our hard freeze on May 19th, one got killed and one got severely damaged, despite having leaves mounded over them and plant containers covering them. If you tend to get lots of “surprises” during spring, you almost can’t protect them too much.

I have some organic fertilizer for acid-loving shrubs that I will scratch into the soil as soon as the rain stops.

How are your hydrangeas faring?

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.

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

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

July 6, 2008

July 16, 2008

July 27, 2008: fully colored up.

September 8, 2008.

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.

This year, my Endless Summer hydrangea is blooming abundantly.

What I did differently

As I mentioned earlier this year, I covered the shrub with fallen leaves in late autumn. I made sure they filled the center of the plant and covered the surrounding soil to a depth of six inches. I did not remove these leaves until I was certain the last frost had passed. New growth had already begun under the leaves. (I also saw some vole tunnels, which I filled in. The shrub didn’t seem to have been harmed.)

When I removed the leaf mulch this spring, I also fertilized with Shrubs Alive! Fertilizer for Acid Loving Plants, to try to enhance the blue color of the flowers. I think they are bluer than when they last bloomed, though not as blue as in the marketing photos.

I also made sure the hydrangea had better weather this year. Seriously, the weather can have a major impact on the performance of these shrubs, and there’s not much you can do about it. This was a good year for hydrangeas, and I’m thankful for it.

Unfortunately, the ‘Forever & Ever Double Pink’ that I fell in love with seems to have expired. After its stunted growth last year and its very weak growth this spring, I’m wondering if it had a virus. On the other hand, the original Forever & Ever Hydrangea (a single pink) had never bloomed for me before, and it now has buds on it. You win some, you lose some.

They’re still high maintenance

The same caveats still apply. They need their mulch in winter, they need their water in summer. Not too hot, not too cold. Ju-u-ust right. Like Goldilocks.

Endless Summer Hydrangea: Dream Come True–or Nightmare?

Hydrangea ‘Forever & Ever Double Pink’ stole my heart in 2006. This photo was taken September 7 of that year

It’s just like Elizabeth said. We gardeners want to believe that our dream plant is out there, just waiting for us to find it. I know when I first saw photos of the ‘Endless Summer’ hydrangea, and read that it bloomed in zone 4, I thought I’d finally be able to grow the same kind of hydrangeas my grandmother did. As you’ll read below, the truth is somewhat more complicated. The same year I got the ‘Endless Summer’ hydrangea (2006), I also received some Forever & Ever hydrangeas to trial, including this one on the left. “Trial” means it came to me straight from the grower, already forced into precocious growth, a good month before my last frost, so its behavior in my garden that first year could hardly be considered typical. My garden notebook doesn’t state when this bloomed that first year, but it was still blooming the first week in September. I fell in love with it.

This photo of ‘Double Pink Forever’ hydrangea was taken September 14, 2007. It never got any taller, and never bloomed.

The following year, in 2007, it got hit by frost after the leaves had emerged. Maybe it got knocked back twice, I don’t remember. (I may forget to cover an iffy plant once in spring, but rarely twice. But there are those nights where the temperature drops much more than predicted.) But when all danger of frost was past, and it started growing, well, it didn’t. Take a look at the photo on the right. I have never seen a woody plant do this. It put out leaves, but the stems didn’t lengthen. Seven inches was as tall as it ever got. You can see the Johnny-jump-ups towering over it in the background. (Click on image for a larger one.)

2007 was a Bad Year for these Hydrangeas

Neither ‘Endless Summer’ nor any of the Forever & Evers bloomed for me in 2007. By all accounts it was a bad year for these reblooming hydrangeas, so let’s not hold that against them.

These are not the old-fashioned hydrangeas

But it’s time to wake up and smell the coffee. Cold climate gardeners, I’m talking to you. These are not the hydrangeas you see growing and blooming in the yards of older homes. These new, fancy hydrangeas, the ‘Endless Summer’ series, the Forever&Ever series, and the Let’s Dance series are all cultivars of Hydrangea macrophylla. These hydrangeas really don’t belong here. They are at the northern limit of their hardiness. For me, at least, they break dormancy well before the last frost in spring. Yet the slightest frost will kill back all the growth, so you need to cover it in spring and fall–every time a frost threatens. Better yet, keep them heavily mulched until all danger of frost is past.

Southern hydrangeas trying to make it in the north

So why are they being marketed to Northern gardeners? Your typical macrophylla blooms on old wood. That means it forms flower buds the year before they are to bloom, and they have to survive the winter. As you might guess, that usually doesn’t happen in our climate. Enter the next generation of macrophyllas: they also bloom on new wood. Even if they die all the way back to the ground (which they will), the new branches that emerge in spring will have flower buds.

But it ‘s not that simple. According to Jim Kohut at Northscaping, our growing season is often not long enough for those buds on new wood to flower. We may get, at best, “one flush late in the season.” For a longer season of bloom, you need to mulch heavily to protect the buds further up the stems.

And that’s not all. Again, according to Jim, these plants need:

• Evenly moist soil, but no standing water
• Moderate air temps during the day
• A low nitrogen, high phosphorus (10-40-10) fertilizer–but stop before August
• Minimal pruning at first–don’t even deadhead for the first couple years

That’s just the high points of his excellent advice. Make sure you read the whole article. You will probably also find this forum thread of interest.

According to Tim Wood, plant hunter for Spring Meadow Nursery (Proven Winners),

If your Endless Summer dies back to the ground in the winter, forcing growth will deliver more flowers and sooner. Endless Summer and other rebloomers have to put on a certain amount of new growth before they will make new buds and flower. So it pays to give these plants extra fertilizer and water to push the growth. Miracle Grow once a week after any danger of frost does the job.

(Note: Miracle Gro is 15-30-15–proportionately more nitrogen and less phosporus than what Kohut recommends.)

Are these prima donna hydrangeas for you?

The bottom line is, you can grow these babies to at least USDA Zone 4–but you have to really want to. They are not low-maintenance shrubs in our climate; they need pampering. If, like me, they remind you of Grandma’s garden, or if you think they’re drop dead gorgeous, you’ll put in the work and be grateful that you can now grow what used to be a shrub for warmer climates.

If you’re hankering for something hardier, try:

• Hydrangea paniculata ‘Grandiflora’ (aka “Pee Gee”)
• Hydrangea arborescens ‘Annabelle’
• Hydrangea paniculata ‘Limelight’
• Hydrangea paniculata ‘Pinky Winky’

These are just some of the more well known cultivars. This Northscaping article mentions even more, plus has additional planting advice for cold climate gardeners.

This is an experiment for all of us. Please let me know in the comments which hydrangeas are working for you.

I wanted one

The Original ‘Endless Summer’ hydrangea. Photo © Endless Summer®

I first learned about ‘Endless Summer’ hydrangea four springs ago and decided instantaneously that I wanted one for my garden, and not just because of those gorgeous blue flowers. My grandma had always had these kind of hydrangeas (H. macrophylla) growing in her garden, and had explained to me that the flower color changed depending on the type of soil it was growing in. I could never grow my grandma’s kind of hydrangea because until ‘Endless Summer’ came along, these shrubs only bloomed on last year’s woody growth, which in my climate would get killed to the ground.

I got one

Last year, I finally got one. My first clue that this shrub might not be without faults was Don’s comment that “they are very sensitive to leaf damage from freezing.” And freeze they did, both last year and this year. In my book, it’s a poor kind of hardiness that makes it through the winter, only to be cut down in spring. Sure, I could use floating row covers on them, as has been suggested, but I wonder if a floating row cover would protect from really hard freezes?

Carol’s hydrangea on June 24 in Indiana

Kathy’s hydrangea on June 29 in New York

I was talking to Carol of May Dreams Gardens (all right, emailing), remarking on the difference in growth between our two plants. Hers is blooming, mine doesn’t even have buds yet! But she was telling me, “I’ve been disappointed in ‘Endless Summer’ because the plants just never get that big. Maybe a foot tall or 18 inches.” Mine is already 18 inches tall, and it isn’t ready to bloom yet. But I don’t think the macrophylla hydrangeas ever get as big as the paniculata hydrangeas, which are hardier and a lot more common (as in the ubiquitous ‘PeeGee’) the further north you go. The American Horticultural Society A to Z Encyclopedia of Garden Plants says H. macrophylla can reach 6 ft. high and 8 ft. wide; it lists H. paniculata as up to 22 ft. high and 8ft. wide. But on the ‘Endless Summer’ website (yeah, a plant with its own website) it says the expected height for ‘Endless Summer’ is only 3 to 5 feet. If we’re going to criticize a plant, we have to criticize it against its claims and not against our experience of other plants.

My shrub also blooms in the same sitting-on-the-fence color as Carol’s: neither pink nor blue, but a bit of both. Since blueberries, which require a very acid soil, grow wild in our field, I had assumed my hydrangea would bloom a glorious blue without any help from me, but apparently the soil near the house is less acid than up the hill.

Not living up to its claims

On the whole, I find this shrub is not living up to its claims. It is not hardy in the way I think of hardy, and it is not perpetually blooming because it takes so long to get going after dying back from late spring frosts. I bet I don’t see a fully colored blossom until August, just like last year.

How about you?

But what about you? For those of you who have planted this shrub, how is it doing for you? Are there others you like better?

He grew the original ‘Endless Summer’

Update: Here’s an article I found about the gardener who grew the hydrangea that became known as ‘Endless Summer’: Tangled Up in Blue. (I had to register on this site to gain access to the article. I’m hoping the link I’ve provided will let you skip that step.)