Resuscitating a hydrangea?
Hello, I have two hydrangeas planted about two feet from the northern side of my house. They get some sunlight in the morning but are otherwise pretty shaded (fthe hostas right next to them are very happy). I don't know what kind of hydrangeas they are because I didn't plant them myself and I've never seen them flower. The short story is that the hydrangeas are slowly growing some new stems and leaves, but not many. The dead stalks suggest that they used to be pretty big. I'm trying to figure out whether they are just slowly recovering from potentially bad pruning or whether they need some other intervention. We moved into the house in June 2015, and the previous owners had hired landscapers to get the property in shape for showing the house earlier that spring. Although I don't know for sure, based on the other work the landscapers did, I suspect that they pruned the hydrangeas down substantially in early March. In the photos I've attached, the dead stalks are what is left of that pruning in 2015. For size reference, the impatiens in one photo is in a 1-pint container. The plants had only a few leaves last year (2016) and didn't show any signs of flowering. Should I let the hydrangeas be? Is there something else I could/should be doing to help them along? Many thanks for your help!
Pruning would not have caused the slow growth you are seeing unless they were wacked down during the growing season, possibly multiple times, to the point that they could not replenish root energy reserves.
It seems unlikely that two hydrangeas were planted this close to each other. (A foot apart?) Hydrangeas are large shrubs. Is it possible that this is a big old hydrangea in decline from age or one that is in decline from poor management practices, and these two clumps are all that is left? (Conversely, it could be two small plants stuck in to fill up space and sell the house.) It is impossible to say why it is so unhappy or so immature that it only produced a few leaves last year. You'll have to be patient.
At any rate, hydrangeas are not full shade plants. They prefer sun or light shade. This may be too much shade for them. You can transplant them to a sunnier spot. They also hate drought. Be sure to water during dry spells for at least the next 2 years until they get going (again?) Even then, hydrangeas should not be allowed to languish in drought (they are the first to wilt in the garden.)
You would not go wrong to apply some compost around these every year. One application of a liquid fertilizer such as MirAcid can be applied too.
If these are standard Grandiflora hydrangeas, they will bloom on new wood from the previous summer. So, don't prune in spring! You'll be cutting off the flower buds. (Actually, the only time to prune is after blooms fade, which is too late to be of any practical help.)
Keep mulch off the base of the shrub (standard for all trees and shrubs.)