The photo is so tiny. Can you take a close up? Are the leaves alternate? If so, it's probably pokeweed.

Hydrangea has opposite leaf arrangement. I cannot clearly see the leaf arrangement on your plant.

Leaves look more like pokeweed to me also. A close up of the flower in better resolution would help.

Yes, most hydrangeas would have more than one stem originating from a crown and this weed looks more tree like. Thank the birds. ;0)

It's not a tree, it's Pokeweed, a herbaceous perennials.

Thank you for your help. I chopped both the pokeweed and the tree down

I'm not sure which tree you are referring to. All the pictures show Pokeweed. Cutting Pokeweed down won't kill it because it has a deep root which will regrow. So you need to dig it out rather than cutting.