I'm submitting the picture not as THE solution but as a starting place to stimulate thinking. Besides selecting plants with the "just right" personality, there's always more that could be added to spice it. For example, the tree could be growing out of a bed of ferns or Hosta; there could be annuals at the left end of the groundcover bed.

{{gwi:47947}}

Ferns, epimediums, maybe hellebores - I'd stick with the deer resistant shade standards, and keep them mostly below the wall height.

I suspect that the most logical thing is to try to regrow grass. Or if grass won't grow, put mulch.

Let's go back to the purpose of the wall, the timing of its use, and the direction from which it is viewed.

Do you ever stand or spend time at the point from which you took the picture? Under what circumstances, and by whom, is it viewed from here? By the kids while playing soccer? So who needs plants?

When will you or anyone be sitting on the wall? Are you ever going to do that in early spring (epimediums) or winter (hellebores)? If you aren't sitting on the wall, you will never see the best season of those or most other shade plants, which is when it's too chilly to sit out.

When does the view from either side of the wall really count? Pick plants, if any, for that purpose, that bloom at that time. For example, you might spend time on the patio in summer, so a plant that blooms in summer and peeks over the wall might be fun - I have a Rudbeckia from the Cherokee Sunset series that might grow in the lee of the wall and you might see flowers over the edge of the wall (blooms even without much sun). Can't remember if it attracts bees though.

We so often have this urge to plant AT things to make them look good, and it never works. (No offense, but look up the side of your house - see that shrub? What, I ask you, is that shrub doing for anyone??) If you want to integrate this wall into its surroundings better from this angle - and it's not bad as it is so I'm not sure you need to do anything - put some complementary "furniture" near it - maybe a stone or wrought iron pedestal or two where I can put my drink if I am sitting there, or a couple of harmonizing containers behind it, but several feet away, just with impatiens or ferns in them - a bit random, nothing geometric. Then tuck maybe one or two ferns or impatiens at the base of the wall, as if they'd self-seeded there, to visually connect the whole thing, and bob's your uncle. You might have to cage the plants to keep the deer away, but you can still easily clean up after the tree. and there is nothing to cramp the kids' style.

Maybe just get those two containers off your patio and put them out here.

But again, I ask, how much does this view matter? I am not sure you have a problem at all.

Karin L

Aren't hellebores poisonous?
The deer don't eat my heuchera, so maybe that's another possibility?
That plus a big pile of daffodils or scilla for springtime.

Bleeding heart is another option.

You could edge the bed with a wide mowing strip made of the same material that the top of the wall is made from. Alternatively, you could edge the bed with the same material used in the patio. But take care to create a nice edge - you have such a pretty setting there you don't want to ruin it with something cheesy or hastily executed. That conservatory you have off to the left of the photo looks especially pleasing!

Maybe show a view from the windows or from a seat at the table.

All I can add is that fine-leaved plants allow fallen debris to drop out of sight more easily than large-leaved plants.

I think that you were right when you wondered if the answer really is to just "reseed...the grass". That nice looking stone sitting wall doesn't need fussy plantings that will be a PITA to maintain. My only other suggestion would be to add a piece of personally appealing outdoor art to highlight the end corner nearest the loungers, maybe along this line :)

{{gwi:47948}}

I normally like to see the entire yard as a whole compostion before suggesting a planting scheme but from the small vignette that you have provided I would suggest planting a light wispy border of plants that would frame the sitting wall and at certain seasons of the year flowering blooms would rise above the wall with swaying color.

We have built probably a hundred sitting walls like this over the many years and have found they usually respond well to being nestled / integrated into the landscape rather than plopped ontop of the landscape.

A mixed border of hellebores, fragrant daphne, ostrich or painted fern, burgandy foliaged ligularia britt marie and chasmanthium latifolium 'river mist' would provide you with deer tolerance, contrasting texture , form and color and provide fragrance.
A small open lilac shrub or weeping snow fountain cherry would add a wonderful sense of canopy if placed slightly to one of the corners.