We have a small back patio with a narrow perennial border along one side. Near the back of the border, a juniper overhangs the bed, dropping needles and bird poop, hogging the rainfall, and making lots of shade. (The tree is in our neighbor's yard, so we can't just cut it down, though I'm tempted.)

I have some struggling astilbe (brown-edged leaves and sparse growth), hydrangea (blue nikko that yields pink flowers, thanks to the acid soil) growing under the juniper now, but I'd like to plant something under there that would thrive. It's a small space and the only shady spot in an otherwise sunny border (with flourishing liatris, sedum, phlox, yarrow, and coneflowers, so ground cover won't look right.

Any suggestions? TIA!
acBee