Hakonechloa or Sedge for under a River Birch?
I would like to underplant a grove of 3 River Birch trees with a shade/part sun loving ornamental grass that does not get too tall, and I have narrowed the choice to one of the Hakonechloa "All Gold" or "Aureola" and a Carex/Sedge grass like Carex oshimensis 'Everillo' or Carex 'Silver Scepter'. I don't have any experience with either of these perennial grasses, but I have read decent reviews for both.
The ground under the river birches is normal (not too dry or wet), and there is some afternoon sun that will hit the grasses through the limbs of the birches. Any suggestions? Thanks for your help.