For scale choose something low. The beauty of the tree includes its trunk and branching. For color, choose something to highlight the dark red in summer and whatever it is in spring and fall. I have many Japanese maples in a variety of sizes and types. One of the best combinations is japanese painted ferns. I also like moss if your site is shady and can be kept moist.

Thank you! Doug can you comment on what those plants are that you added in the bottom pic?

scabiosa, bobo sedum, blue rug juniper

You think I could somehow do a combination of japanese painted ferns and elijah blue grass?

Friendly bump to get a fresh set of eyes and hopefully ideas. All the lavender didn't make it, not sure why. Was hoping to replace it with low lying flowering plant underneath the weeping japanese maple. Any thoughts?

Have no idea where you are located so very difficult to make any meaningful suggestions - what may work well in one part of the country may not work well in another.

You should also be aware that Japanese maples have a very delicate surface-oriented root system that resents dsturbance. In fact you can activate or even introduce some pretty serious soil pathogens that could take out your tree if you damage the roots. So any underplanting should be something that can be left undisturbed.....like a spreading groundcover.

Planting beyond the canopy/dripline is a bit more flexible but you still need to be careful and avoid excessive cultivation. And whatever plants you choose should fit the sun conditions and water requirements. It's hard to reconcile combining a full sun, drought tolerant plant like the blue fescue with a moisture and shade loving fern.........

Thanks for the helpful comments! I just outside of Washington DC, hardiness zone 7a. Any thoughts on a ground cover flowering plants that would work?

I really like Veronica peduncularis (umbrosa) 'Georgia Blue'. Very low growing, intensely blue flowers produced in abundance in spring followed by sporadic flowering the rest of the season. And it is evergreen and the foliage turns a rusty, purplish-bronze in winter. Adaptable to both full sun and moderate shade.

Thanks! I love this suggestion and will likely go with it! Do you know how the Georgia Blue is different from the blue creeping phlox?

The phlox is not fully evergreen and usually looks pretty ratty in late winter. And needs full sun for best flowering. Also has a much shorter bloom season.

Went with your recommendation and put a few Georgia Blue in over the weekend. Local nursery only had 6. I think I need a few more around the back of the tree. What do you think?