The house I'm living in came with a big hydrangea by the porch and a smaller one on the side of the house. No idea what variety they are, though with the age of this place it's likely they're an old one. I pruned the big one late last fall (discovered later this is not the time to prune hydrangeas) and it's coming back, but low on the branches, with a good food and a half of dead-looking wood above the leaves. No sign of blooms yet, but this is also true of the bush I didn't touch on the other side of the house.
Should I do anything for these plants, or, given my track record, should I just leave 'em alone?