I know more about roses than I do about other plants which is why I joined ATP. I want to extend my plant pallet and I think the very best way to learn about plants is from people who grow them.
We each develop our own garden philosophies as we move through our gardening journey. One of mine is not to fight the inherent nature of the plant I am siting. In other words, don't plant shade plants in full sun or plants that need sun to thrive in shade. Or plants that need well draining soil in heavy clay, etc. To me, it's worth the effort to find the plant that will thrive in the site without my having to do a lot of extra work to make the plant happy.
As for your shaded 'Dublin Bay', you said, "Oh, and Roseblush, it's not near a tree--it's the house that shades it on one side and the oaks throughout the backyard that shade it on other three sides. It gets sun, though, I promise. For a minute or two at noon (probably). "
I have a hunch that DB will never thrive in that location because roses do need more sun, so again, it's time to re-think what would thrive there and make you happy.
Although, they are not climbing plants, have you thought of planting huercheras in that bed ? If I had enough shade, they could become a true passion for me because I have always dreamed of having a foliage garden with contrasting foliage that sets off the plants in the bed. I have enough flower beds, I think it would be delightful to break that pattern and have a 'just foliage" bed. Although some of the newer introductions do have more flowers and re-bloom, it's the foliage that calls my name.
Here's a link to an article on ATP that made me start drooling ....
http://garden.org/ideas/view/g...
I'd move that DB out of there in a nano-second and create a foliage bed filled with huecerhas with contrasting foliage, and put the rose where it could have more sun instead of hoping it would thrive. For height, I might include an understory tree that likes shade ... possibly a Japanese maple ... more foliage contrast.
btw ... you might use a sturdy plant stand to hold the container up higher rather than trying to attach a bracket or whatever is structurally required to bring a container up higher. There are so many possibilities. Keep dreaming.
Smiles,
Lyn