These look like Bigleaf Hydrangeas or the Hydrangea macrophylla type hydrangeas.  It is difficult to say if they are the repeat blooming type or not. A lot of the new cultivars of the macrophylla species are reblooming, either way though you can wait for the spring at this point to prune off any old dead wood or to add more shape to the plants. You can wait until the first flush of leaves and blooms come and then prune no more than 1/3 of the plant. In time they should fill out more and you will have more blooms. 

Let us know if you have further questions. 

Emily 



No, the macrophylla species is not native. Our 'native' Hydrangea consist of: 

Hydrangea arborescens  - truly native to Maryland and the many cultivars that are more showy - 'Incrediball' and 'Invincibell' are some  and there are many more now. The Incrediball seem to be the only ones of the cultivars that are fragrant and attract pollinators.

Hydrangea quercifolia is native more to the south east but still grows well here.