Do hydrangeas continue to blossom?

I have very little sun in the front or back yards, too many mature trees. I could only put it by itself way up on the second tier in the back yard where there is sun pretty much all day. My son has a 19 month old white shepherd that is over 100 pounds and loves to play fetch and would probably run over it. I had to put up an eight foot fence to protect my veggie garden because he and the shepherd mix that is almost 100 pounds could flatfoot my four foot fence without touching it. Lost almost half of my green beans and squash last year to a squirrel running the fence line on the other side of the garden.