Endless Summer and Forever and Ever Hydrangeas: Growing Tips for Cold Climates

– Posted in: Hydrangeas
46 comments

Endless Summer Hydrangea: Dream Come True–or Nightmare?

Image of a double pink flowered hydrangea

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.

Image of hydrangea with ruler to show its 7 inch height

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.
Last fall I mulched my big leaf hydrangeas. I'll probably uncover them this week.

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:

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.

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.

In its own way, frost may be one of the most beautiful things to happen in your garden all year . . . Don’t miss it. Like all true beauty, it is fleeting. It will grace your garden for but a short while this morning. . . . For this moment, embrace frost as the beautiful gift that it is.

~Philip Harnden in A Gardener’s Guide to Frost: Outwit the Weather and Extend the Spring and Fall Seasons

43 Comments… add one

Deb October 14, 2014, 8:05 pm

All your posts are informative. I am a first timer with an Endless Summer Hydrangea and can use all the help I can get. Since it is Oct. I am wondering when I need to cover them. Do I wait for a hard freeze?, the temps are still in the 60’s. I think I will try the open ended box filled with mulch will cypress mulch do? thanks

Kathy Purdy October 14, 2014, 8:19 pm

I think I would wait for a hard freeze–unless snow is in the forecast. (That has happened to us; we get snow before the ground freezes hard.) You want to protect the flower buds from severe cold but you don’t want the shrub to grow more after you put the mulch on. If the leaves are all brown that would be another sign to go ahead and mulch. I am not familiar with cypress mulch but you just want cold protection. The mulch should be light and fluffy.

Bonnie September 30, 2014, 10:46 am

I purchased 3 Endless Summer Hydrangeas about 7 years ago and all I get each year are nice green leaves each summer. I live near Lake Placid, NY and it’s very common to get temperatures 25-30 degrees below zero in the winter.
Anyway, this month (September) I bought some burlap to wrap them before the snow flies, but we received a heavy frost a couple weeks ago and all the leaves are black. Should I not even bother wrapping them now?
Thank You.
Bonnie

Kathy Purdy September 30, 2014, 6:21 pm

What you are trying to protect with the burlap are the flower buds close to soil level, so the burlap still serves a purpose. You might want to read Hydrangeas in the North: Getting Blooms in the Colder Climates over the winter and try implementing Tim Boebel’s advice come next spring, although his idea of north is not as cold as Lake Placid. And unless you are stuck on having blue blossoms, you might want to consider the many lovely H. paniculata and H. arborescens cultivars, which are far hardier than any of the H. macrophyllas that supposedly bloom on new wood (such as ‘Endless Summer’). Good luck!

jrw June 26, 2014, 7:42 am

I live in suburb of Chicago. I have one Endless Summer hydrangea that has been growing and blooming like crazy for years (I bought it when they first came out at the Big Box stores). Many years I didn’t even get around to fertilizing. BUT, last year I did a heavy pruning (I know, my bad; Fall or Spring, don’t remember) and got NO BLOOMS whatsoever. This year I did not cut back, but of course we had the polar vortex. The plant looks healthy and huge, but no blooms again. Any ideas why? One other thing I did do last year and again this spring was added some expensive “Color me Blue” to the soil, as well as some Osmocote plant food. Hmmmmm…could this be the problem?? Thanks for any advice!!!!

Kathy Purdy June 26, 2014, 9:29 am

The fertilizer is not the problem. The polar vortex is your problem. It probably killed the buds on the old wood, which provide flowers early in the season. You will probably get flowers later in the season, the ones that form on new wood. Thanks for stopping by and taking the time to comment.

RJ March 21, 2014, 9:56 pm

My “Endless Summer” hydrangea plants have been in their zone 4b site (Mn) for several years. For me the secret to getting good blooms is to not do any pruning until you can see the green bud forming, than only prune as necessary, up here or down here depending on your reference that works out to late May or early June. My plants are currently 4′ x 4′ and have been in the location for several years vs my mothers in Zone 7 which is huge in comparison. The only problem I have had is when there has been insufficent snow cover for insulation.

Bob October 9, 2013, 8:35 pm

When are good times of year to divide and transplant mophead/macrophylla hydrangeas on Cape Cod, MA (zone 7a)? What is the best time? (I’m wondering if it matters if I transplant in October, November, December or March). Any tips for digging up and dividing some large (5 feet), 20-year old hydrangeas that I must move because we will be expanding our front steps next spring. Hydrangeas grow very well on Cape Cod. Thanks for any advice you have to a newbie!

Kathy Purdy October 9, 2013, 8:59 pm

I really don’t know. I suggest you contact C. L. Fornari at http://www.gardenlady.com/. She lives on Cape Cod and has a much better understanding of the local climate.

joan castellano June 30, 2013, 6:52 am

I to have forever hydrangeas, I have had beautiful blue blooms but now they have turned brown. do I need to cut them back in order for it to bloom again? also the leaves r turning brown, we have had a lot of rain this june could that b the reason? they r in full sun all day.

Kathy Purdy June 30, 2013, 5:32 pm

I would definitely cut off brown blooms. It does sound like your plant is getting some kind of disease, which could be moisture related, but I really don’t know enough to make a definitive diagnosis. Try Cooperative Extension or a local garden center.

Barbara April 6, 2013, 7:19 pm

I moved to Massachusetts from NJ in 2002 and I wanted Hydrangeas. I found a site online called “Hydrangeas Plus” which sells Mophead plants for zone 5 at a reasonable price. They are all leafed out with buds and sent with rootball intact. I never had a problem with anything I bought from them. I am back in NJ now and can grow just about anything.

Karen stads September 30, 2012, 11:05 am

I live In Saskatchewan and have an endless summer hydrangea that hasn’t bloomed in two years since we bought it. I’m wondering if we should cut it back this fall or in the spring? We haven’t cut it back before but I was just wondering if this would promote blooming. Thanks!

Kathy Purdy September 30, 2012, 11:11 am

You need to protect it from cold, and possibly give it more sun. It blooms on new wood, so cutting it back just removes flower buds. It is a southern plant, so the further north it is, the more sun it needs.

Karen stads September 30, 2012, 11:21 am

It is in full sun all day so I was thinking it might be getting too much sun! Last summer the leaves burnt from the sun so this year we have been giving it lots of water and there was no leaf burning. I heard it blooms on old and new wood. In the winter we insulated the plant and it came back fine in the spring . I’m just not sure what else to try!!

Kathy Purdy September 30, 2012, 11:54 am

The “old wood” that it blooms on is flower buds close to the ground. These are what must be protected, and Saskatchewan just might be too cold. There is a book, Hydrangeas in the North: Getting Blooms in the Colder Climates and I’m afraid he calls our USDA zone 6 a cold climate! I believe ‘Endless Summer’ is supposed to be hardy to our USDA Zone 4. If you aren’t determined to have blue flowers, there are hardier hydrangeas that will bloom in white or pink.

Pamela V. July 16, 2012, 12:55 pm

Hello, I bought a what i believe is a summer hydrangea–are they the only ones that are blue? Anyway, after reading these posts, I would like to know the best way to prepare the soil to transplant it. In zone 5, I believe i will at least get blooms tho the plant will be short. It is in a pot now, i thought tho bury it and transplant next spring. I just want the soil as perfect as I can get it so I get both blooms, and blue ones!
Thanks.

Sara, but not the first one. May 19, 2012, 7:59 am

Sara in Atlanta, here. Or as we call it Hotlanta. Thank you all for the true information on this plant. I am fixing to buy it to give as a gift and was not sure if it really bloomed as stated. We have the opposite problem here, as everything gets scorched in July and August. I already have the old style plant and was going to tell you I do have to water it to death. Still love it. The problem here is that it can get cold, got to 9 below about 20 years ago. We were not prepared. Cars with frozen radiators were littered on the highway. My camelias froze to the ground. They did come back but it took about a year for the green to poke out. I have tried to grow semitropical plants here that are supposed to live through winter. Did not happen. My advice to you is to stick to stuff that grows in your climate. I got sick of dragging in bananas oleandor etc. into my garage. It’s always fun to see if something will grow in your climate. But the charm of where you are is the native plants. I don’t want to come to where you are and see the same old stuff I left in Atlanta. Thanks!

Debbie April 12, 2012, 1:57 pm

HELP!! Ive had my 25 Endless Summer Hydrangeas for 5yrs.. every year we’ve had gorgeous flowers and every year the plant got bigger & bigger with more flowers . All of these plants border a walkway leading to another deck in my backyard .. Its the STAR of my backyard… I pruned all the dead flowers correctly as I always do and the new leaves and buds were growing yet again UNTIL LAST NIGHT!!!! We had a very mild winter and last night we had a fluke late frost. I never thought to cover these gorgeous specimens. I covered everything else but those beauties.. I woke up this morning and all of the leaves are drooped, getting black in color and any new buds are mush.. What can I do to get these plants back to life or will I not get any growth this year because of the damage that’s been done in one night????? Will I have to buy 24-30 new plants and start over again? Please let me know what to expect.. right now I see the row of what was once the most gorgeous entrance on my deck that used to shape my walkway become wet mops of leaves.. I need someone to help me with this. Im devastated over losing them if thats the case.. SHould I dig them out and buy new ones or leave them alone and see what happens? Desperate in Asheville, NC!

Kathy Purdy April 12, 2012, 4:36 pm

Hi, Debbie, sorry to hear of your unexpected frost. Your plants are still alive, I suspect, and will grow back from the roots, as long as they don’t get another hit like they got last night. But they will take a lot longer to bloom, as the early flower buds were killed with the cold. I would not dig them out. I would remove dead leaves, but not prune anything until new growth emerges and you can see exactly what part of the branches have died. They will probably not be spectacular this year, but will be back to their old selves next year, as long as you remember to cover them when frost threatens. I have to do this every year with my ONE ‘Endless Summer’ because it always wants to start growing before we are done with frosts and freezes, which is why you’ll never see me buying 25! But it has been a strange winter and spring for just about everyone.

Donna July 19, 2011, 11:58 am

Can I use Miracle Grow Fertilizer 24 8 16 to keep my hydranges Blue. Would you suggest using something else. Thank you

Kathy Purdy July 19, 2011, 4:24 pm

MiracleGro won’t do it but MiraAcid will.

Shirley July 3, 2010, 12:43 pm

I too have an Endless Summer Hydrangea and planted it where it faces east getting morning sun and afternoon shade from about 1:30 pm on. I made a burlap screen and filled it with leaves but it still died right back to the ground. I live in zone 3b. Has anyone done anything different in my zone that has proven successful in preventing dieback to the ground?

Sara April 14, 2010, 10:46 pm

Okay, new question on this old thread…

Zone 4/Minneapolis — My Endless Summer hasn’t bloomed since its second season but in hindsight I hadn’t mulched them enough. We have had an early spring warm up this year so I’ve got tons of green popping up — should I recover the green until later in May?? Will the new green growth die if it doesn’t get light?

Kathy Purdy April 15, 2010, 7:30 am

This is a tough one. There is more than one factor affecting bloom. They take longer to bloom if the cold gets at them in the winter, but if they don’t get enough summer heat they don’t bloom (or take so long to bloom it is the same thing) either. If you had a cool summer last year like I did, that could be why it didn’t bloom last year. Given how long we have to go until we are clear of frost danger, I would mulch the base of the plant with something light and fluffly, and resign myself to losing the leaves to one cold spell or another. Or you could cover the whole thing with a sheet every time frost threatens. My winter was not as cold as usual. The forsythia that often get bud-killed are blooming spectacularly, so I bet if we hadn’t had this warm spring to lure the hydrangeas out of dormancy early, they would be really great this year. The trick is to keep them from the spring cold until spring is really and truly here. Let us know how things turn out for you.

Carol June 6, 2009, 2:01 pm

I planted 3 hydrangeas on the East side of the house (slab – no floor heat) 2 years ago – I love all of them & they all survived the long stretch of minus 40 degree weather last winter. In fact they are all leafing to about 2 feet up – I pop a cardboard box around them in late fall & fill with mulch, then remove it gradually in the spring. Its easy todo – no heavy work involved. I’m in zone 2B – 3A (Alberta); the hydrangeas I have are Pinky Winky, Annabelle, & my favorite – Quick Fire.

Kathy Purdy June 7, 2009, 9:11 pm

Thank you for sharing your tips, Carol. I imagine you have to stockpile the boxes to make sure you have ones that are big enough. Do you use fertilizer? If so, what kind?

Carol August 19, 2009, 1:19 pm

Sorry I took so long to reply – haven’t been following the posts – all I did was set the box over the plant ( with bottom & top open) & dump in the mulch you can get at any greenhouse – cedar, I believe. Once you put the box on & fill it, there’s no problem with it coming off – for extra insurance you can just be sure the flaps at the bottom face out & throw some extra mulch on top of that. In spring, be very gradual at removing the mulch, as you don’t want the new growth to freeze. I’ve not had any problems, so I’m sure it should work for you.

Beth July 9, 2009, 9:37 pm

All 3 of those (pinky winky, annabelle, and quickfire are beautiful, but they are all the more hardy varieties. If you love those limelight is really nice too! I am in zone 6, attempting to grow the mophead varieties, such as endless summer, and seem to have done well since I covered them in mulch surrounded by a chicken wire cage this past late fall / winter into the spring when all chances of frost were gone. They are blooming beautifully, and I am so so excited!!

Wanda August 16, 2009, 7:55 pm

Hi Carol, just read your article. I have been searching for information on how to keep my Quick Fire alive through the winter. I live in southern Saskatchewan Zone 3A. Just wondering what you used for mulch. Also how did you secure the cardboard box to the ground, did you have an internal frame to support the cardboard box? I just bought the shrubs this year so any additional information would be appreciated. Thanks bye for now—-Wanda

monika May 1, 2009, 7:05 pm

I received a Endless Summer for mothers day in 2008,I live in zone 6 the plant started to die back right away ,as of now I have nothing but a few dry twigs, i don’t believe it will come back at all this year . What did I do wrong? Any help would be welcome, I love these plants and would like to have a few in my flower bed.

Bob July 8, 2008, 12:07 pm

I have two of your “endless summer Hydrangeas given to me by my sister 3 yrs ago. They are doing fantastic here on cape cod. the first year a little stunted.
question: I have a number of other types of Hydrangeas here, what we refer too as “Nantuckett Lacy”…they have given off many new plants that are 3-5 feet tall. i would like to transplant and move. When is best time of year to do this here on Cape Cod, MA?

Jackie June 20, 2008, 7:02 am

My experience with Endless Summer is that they appear to thrive on benign neglect. The more I ignore them, the better they seem to do. In WI, I encourage my clients to plant them in part shade, water slightly less than they would with most hydrangeas, and avoid pruning for the first several years. The most common issue that I’m seeing here is that they flower beautifully the first year (reel the client in with promises of gorgeous blooms) and then never again. I have to say, what I’ve read here is interesting, and I may try the fertilization thing, but so far—I’m just not impressed with Endless Summer’s performance in zone 4-5. I’d recommend Quick Fire or Limelight first.

Beth July 9, 2009, 9:41 pm

Any mophead in a climate that freezes must be covered for the cold months, and not uncovered until there is no risk of frost. Mulch, straw, or oak leaves are good choices to cover them with. I have heard maple leaves are a bad choice though. You can use a box or chicken wire or a trash can with the bottom cut out to keep the hydrangea covered in the mulch / straw / oak leaves. This protects the wood and flower buds from dying from the frost.

Nan Ondra June 8, 2008, 9:31 am

I had a nearly identical experience with those Forever & Ever trial plants here in mid-Zone 6: One or two blooms on one of the four the first year, then nothing last year. They have a fair bit of short basal growth this year but otherwise don’t look like much. I’m not really into fertilizing or pampering them, so if they don’t perform this year, they’re compost fodder. The paniculata types perform beautifully for me, though, and so does Hydrangea arborescens, even in full sun.

Julie June 5, 2008, 7:02 am

I had beautiful hydrangeas (the older macrophylla, Niko Blue) that we planted and were huge by the time we sold our home after 8 years. We moved to a new home and I planted the Endless Summer and they look so small and almost look like they have “shrunk” since last summer when they were purchased. I mulched and covered with leaves and nothing is growing on the old wook like everyone says – can that be pruned back?

Thanks!

Carol, May Dreams Gardens June 4, 2008, 8:03 pm

Good info. My ‘Endless Summer’ hydrangeas bloomed last year in my zone 5 garden but never got more than a foot tall. We had such a cold miserable April, I think it knocked them back a bit.

This year, so far, we’ve had an ideal spring so they look much better.

Carol, May Dreams Gardens

bestgarden1 June 4, 2008, 12:00 am

I will try the named company fertilizer for growing the plants and see what the difference between the previous and now. This is the nice post.

Mr. McGregor's Daughter June 3, 2008, 3:29 pm

I have both ‘Endless Summer’ & ‘Penny Mac.’ I’ve found that ‘Penny Mac’ is the superior plant. It did manage to bloom last year & this year it already has 1 large bloom cluster in bud & 1 forming. ‘Endless Summer’ is still nothing but leaves. I treat them both the same & have never fertilized them. I think I’ll try the recommended fertilizer & see if it makes a difference.

Don June 2, 2008, 7:13 pm

Excellent post! Next year I’m going to fertilize and see what happens (maybe a third of the terminals have flower buds this year).
don

Gail June 2, 2008, 9:08 am

Zone 6a/6b and I can grow Oakleafs and Arborescencs very nicely; the rest require way more work than I care to give them. A very informative post, Kathy and I might give Limelight and Pinky a look to see if they can be happy here in my growing conditions.

Beth July 9, 2009, 9:44 pm

Limelight and pinky winky do VERY well in zone 6

Muum June 1, 2008, 11:04 pm

this is such good info! I am a zone 5-ish high altitude Utah gardener, and I have a hydrangea or two that I am nursing along (and heavy mulch is part of the strategy. the oldest one is struggling, though. I’ll check and see what kind I have!

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