When should I prune my damaged hydrangea?
I have been receiving the newsletter for years, this is my first time writing. I have two hydrangea trees that are about 5 ½ feet tall and 7 feet, that were planted about four years ago. They are in bloom and the blossoms captured the rain enough to bend the branches. On the smaller of the trees a branch was too stressed and now has peeled open. I can look into a 5 inch “wound” that looks a bit like an open taco. The weight was obviously too much. The branch that is broken comes right to the main trunk. There are two other larger, less overloaded branches. My question: how and when do I prune this “open wound”? Should I cut down the other two branches as well? The tree will be very lopsided if I do not also address the healthy branches. Should I “knuckle” all of the branches and make it look like only a tree trunk exists with the hopes of development on new branches next year? Should I do it now, wait until October? Are there other things I am not considering?
Pamela Hargest, Horticulture Professional
You could remove the wounded branch now. I would do it incrementally, reducing its weight in stages, then make the final cut right outside the branch collar where it joins the main trunk (leaving the bark ridge and branch collar intact so that tissue will close over the cut). It should be late enough in the season that doing this will not stimulate a flush of new growth.
You could remove a portion of the wounded branch, just to reduce its weight and prevent further injury, and take the remainder of the branch off after the tree has gone fully dormant, perhaps even waiting until next March. There would be less likelihood of pathogens entering the final cut at the trunk if you did it this way, and calluses would begin to form quickly over the cut as soon as the tree breaks dormancy in April.
I would wait until early spring to do any further pruning to shape the tree. Here is more information about pruning: Bulletin #2169, Pruning Woody Landscape Plants.