Few plants have made such an instant splash as ‘Endless Summer’ hydrangea when it was introduced to the public in 2004. Here was a hydrangea reported to bloom 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. Northerners covetous of these gorgeous blossoms could finally enjoy the beauty that Southerners know every June.
While Northerners salivated over ‘Endless Summer,’ reviews from many Southerners were mixed. Yes, it bloomed beautifully on both old and new wood until the end of June. Then when it got hot and dry, the way it almost always does down here, the plant entered suspended animation and never produced another blossom that year.
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. You’re wilting every day when I get home from work, expecting me to attend to your needs before I go inside and pop open a beer. No way. Beer comes first.
So you decide to get even. After two weeks of hot, dry weather, you proceed to hibernate. Oh, you’ll keep your pretty green leaves all summer. But no matter what I do from then on, you won’t bloom again. Nosiree. You’ve shut down for the summer.
To be fair, this reaction occurs more often on new, small plants than older, established plants with large root systems. So maybe you and I should be a little more patient. We should also take comfort in the fact unlike older hydrangeas that bloom only on last year’s growth, ‘Endless Summer’ is immune to the vagaries of compulsive and badly timed pruning. You can prune the heck out of it in fall, winter, or spring and still get flowers.
But if you demand repeated, endless summer blooming right from the start, do what I do. Plant it in a nice, big container that you water and fertilize regularly like you do with your other potted plants. It’ll be so happy thinking it’s back at the nursery. You’ll be happy too.