Buds go brown
Hydrangea blooms can’t take the heat
Q: My hydrangea blooms have all turned brown. I have more than one
kind like you suggested, but my blooms are already gone for the season. Help!
— Angie from Youngstown
A: This has been a challenging year for hydrangeas in the garden. Unlike last year when we had a slow warm-up in spring with no hard frosts and an abundance of rain through July — this year was a challenge.
We had some early warm-ups, followed by cold spells and some hard frosts. We had early rains, but it was hot quick and very dry throughout the Mahoning Valley. So, it was not the best weather for hydrangeas — unless you planned for such a scenario.
The early changes killed nearly all of the buds on old wood for the macrophyllas and even a small number of buds on the oakleaf hydrangeas. The dry conditions forced many blooms to fade from white / cream to brown quickly — leaving out the faded pinks and chartreuse greens that make the flowerheads more interesting after full bloom.
What can be done? How can hydrangeas produce better and keep their beauty longer?
Planning, taking notes on what ones do the best, noticing when certain ones are not performing the way they should.
This year was a good year to take note of the location of your plants. Some of the early blooming smooth hydrangeas and oakleaf hydrangeas turned brown because they needed more water to support the blooms. The same can be said for paniculata hydrangeas, but even moreso because of the high temperatures we experienced when they started to bloom.
All hydrangeas are shade-loving plants. Some tags say they can take full sun — but that means those plants need a LOT more water to keep blooms looking good during the summer heat. Nearly all hydrangeas should have morning sun to dry the leaves until just before noon. That’s only three to five hours of sunlight per day, followed by dappled shade the rest of the day.
For more information about the five major types of hydrangeas that grow well in our area, along with some suggestions for cultivars — check out my factsheet at http://go.osu.edu/hydrangeafacts.