Pruning ancient plant of large snowball variety
A very large plant that has been on our lakefront for decades had a bad season last year -- drought followed by biblical rains followed by over 100 inches of snow, with ice on the lake into April. I don't know what it is. Its flowers are large, white, drying to pale green. It is tall and wide.
It had lots of dead branches this year which did not get pruned. It is not its former robust self this year. I can guess that this plant has never been watered and never been fertilized. It's in a public/common area, so no one really takes ownership of it.
So, if I choose to take it on in the spring, what should be my course of action, beyond cutting out all the dead wood?