Underground Black wasp
They love my Hydrangea bushes. They are by my front door. They attack me every time I open door. I need to detour them there is no way to ignore them. Guest can’t even come in. Help
Minnehaha County South Dakota
Based on your description the most likely candidate is a pompilid wasp. These are solitary ground nesters that hunt spiders and other smaller arthropods to use to provision their young. They can be territorial, but are not considered to be super aggressive to people. They are most likely attracted to the flowers (they use nectar as their food).
They are very aggressive. I can’t go out my front door without them flying all around me.
There is a difference between aggressive and territorial. I also have wasps (at least 5 species) around my back door because of my milkweed patch, and while they do sometimes buzz me as I'm walking through they do not try to sting me. They're way more interested in the flowers and I'm not actively threatening their nest.
When we hear about wasp stings, it's usually in connection to their nest being threatened (i.e. mowed over in the case of yellowjackets or when someone tries to take down a paper wasp nest that is still in use).
There's not a great way to get wasps to move without altering the environment by your back door - clipping the flowers so they don't have a nectar source.