I credit my paternal Polish grandmother for my life-long love of plants and gardening. She had a large vegetable and flower garden on a small lot in the city of Stamford Connecticut. She was probably the only person I know that was able to coax a gardenia to bloom indoors.
In particular I remember that she had a hydrangea with big puffy white flowers. Seventy years later I’m growing an Incrediball Hydrangea with foot wide puffy white flowers. my Grandmother would be proud.
I have a few other types of hydrangea, a climbing variety and Pinky-Winky (Paniculata).
However all is not perfect in my New Hampshire garden. Specifically I lack blue blossoms such as these that surround houses and businesses at Cape Cod.
It is not for lack of trying I planted one Nikko Blue and two Endless Summer Hydrangeas. These varieties are hardy in my zone and can be coaxed into blue blossoms with a dose of acidic aluminum sulfate. Even though I purchased them in blossom, it would be the last time they would flower.
In conclusion, ten years have past. the Nikko and Endless Summer have beautiful leaves, they look healthy and come back every year with another crop of leaves. I travel to the Cape to see blue flowers.
Okay John. Adding acid to the soil is only one step. Do you cut them back in the fall? Don’t!! Nikko Blue set buds on previous years wood. This is a common mistake. Another possible is winter kill. Do the plants send up growth in the spring only from the crown? I’d so, and you’ve not cut them down, then winter kill is the culprit. If the shrubs are not very big, after they drop leaves in the fall, gather the branches as close together as possible with twine. This will cut down on the wind damage. Putting up a burlap screen is good too. Nikko Blue are generally Hardy in Zone 6 – 9. We are in zone 5, so a hard winter can be causing winter kill. The endless Summer Variety was supposed to be more forgiving of the new vs old wood. But winter kill can be a problem too. Instead of using aluminum sulphate, try just sulfur. Espoma makes a good soul acidifier with sulfur or for a more complete fertilizer, try Espoma Hollytone.
Excellent advice. I never cut them back since I know they produce on old and new wood. I am going with the winter protection strategy that you suggest. You may be my “go to” authority on gardening tips.