What is happening to my hydrangea?

Asked September 12, 2015, 5:50 PM EDT

This is some kind of a hydrangea. My husband bought it 10 years ago and can't remember the name. It blooms early spring and then not again. It had gotten so big that last year we gave it a good pruning. I don't know if we over-pruned or if the dry winter was too hard on it or . . .? One half of it looks dead although when you get close some branches did produce small buds that never opened. Some greened out and flowered but then two weeks ago the leaves on part of the relatively healthy-looking part crisped into brown/red. I hope this picture is fairly clear. I'm not sure whether to cut it all way back, leave it alone and see what happens next year, or if it's diseased and should be removed. Any guidance appreciated.

Hennepin County Minnesota hydrangea pruning hydrangeas

1 Response

There are several things in your post that don't make sense. Most hydrangeas bloom in the summer. Exceptions are hydrangeas that bloom on new wood, and these are often marginally hardy here. Your photo shows a tree form, or a large woody shrub. The only hydrangeas that fit that description bloom in the summer.

Are you sure you have a hydrangea?

Hydrangeas withstand heavy pruning, other shrubs do not. If it is some other shrub or tree, your heavy pruning stressed it. The damage I see in the photo could be from the pruning or from winter-kill. In either case, it is not a disease that will spread.

Here are two things you can do. First, determine what the plant is: genus, species and variety. Second, keep your plant well hydrated into late fall. Do not prune. Wait until next spring and see what happens.

Here is a link on hydrangea care: