Black Diamond crepes are lower growing varieties, with arching, spreading foliage. Often recommended for more of a hedging type of planting. They will have fairly dense foliage that shades out the underneath. I have a similar crepe planted along by my road. While it's small I opted to let re-seeding vincas grow through the mulch, but mainly it's just mulched. Since it will be low growing and 8' wide, it could be hard to get underneath eventually, and my other crepes seem to only let certain things grow under or near them. By one I have a rose doing very well, and had some ground cover oregano which has more recently died. Another rose, some coreopsis and some becky daisies were not all that happy or is a clematis. These all used to do well (and are not in shade) pre-crepe...thyme however has proven to be a wonderful ground cover underneath all the trees.

I am so grateful for your post ! I was planning on planting the 4 to make a 21' square. Trying to subdivide - in a somewhat formal way, my football field sized back yard. These trees I purchased for this purpose that they wouldn't be too tall to block the borrowed views that are beyond which are beautiful. Also- I thought the black foliage would be lovely against the green lawn. I wanted to create 4 isosceles triangle beds to create a " room " inside the Football field. I'm loving your rose idea ....shrub roses could be pretty & use up more space ! I like it !!!

White roses !!! Against the black foliage, hot pink flowers ! Love it !

Better yet - white phlox - does very well here, crazy long bloom time, mildew resistant apparently We've only had about 999" of rain since April