On Friday when I mentioned the “clematis controversy,” I also mentioned something I called ‘hydrangea hysteria.” It was a catchy little phrase I thought up to sum up the fact that without a doubt, in my gardening career, I have answered more questions about hydrangeas than about any other plant that exists.
The growers and breeders have done more in the last 10-15 years to make hydrangea growing for vast parts of the country easier than ever. But because many of us still have older varieties of hydrangeas–or because many folks, at least in my part of the world travel to Cape Cod and the islands and see the magnificent hydrangeas that they grow there–everyone wants those lovely blue-ish purple hydrangeas that are grown “on the Cape.”
Short of moving to the Cape, or doing copious amounts of soil amendments, and making sure that folks like the Spoiler stay away from old-fashioned varieties that bloom on old wood (do you begin to see some of the issues with hydrangeas?), there’s no reason that ordinary folks can’t achieve beautiful blooms every year.
I thought about this again when I was at one of my recent garden club lectures and overheard one club member telling another–or perhaps remarking to the whole club–“remember the problems we all had with our hydrangeas last year? Well, I didn’t cut mine this year and I have beautiful blooms. So that seems to be the trick.”
I didn’t say anything–who am I to argue with success–but last year I and everyone I knew had almost no blooms at all. This year, I did exactly the same thing as last year–I pruned my dead wood out. I fact, I probably did it a little later than normal on half of them because I had a late spring cold–and I had beautiful blooms. If anything, this winter was more severe than last. And I have many varieties that bloom on old wood. Those are blooming a little less vigorously at the top but they are still blooming.
What determines whether the varieties that bloom on old wood will flower is whether there is a late frost to kill off all the buds. Clearly there wasn’t one this year and there was one last year. Varieties that bloom on old wood should be pruned after flowering in late summer or fall, if they need to be pruned at all. Only dead wood should be removed in the spring.
That’s why I and almost every gardener I know am planting the newer varieties that bloom on old and new wood, or varieties like smooth hydrangea that flower regardless of the cold (they bloom on new wood so they too can be pruned in the spring if you have die back or decide you want to shape the plant.)
My “hydrangea hedge” is made of two such varieties. Endless Summer (the blue hydrangea) is a re-blooming hydrangea that flowers on old and new wood. Invincibelle Spirit is a smooth hydrangea that flowers on new wood. And I think they look nice together too.