I took a screenshot of the copyrighted photo, (see attribution at the bottom) but here's a great link to something doable for me. But I can't really figure out what most of those plants are. I've already considered either little bluestem or prairie dropseed as my grasses, but still working on the flowers. Prairie Moon Nursery, a fave of mine, is sold out of most of what I would want to buy bare root. I could possibly try some seeding this fall and plant some other stuff around the area in the meantime. The tree will be very small this year anyway . . . https://www.prairiemoon.com/geum-triflorum-prairie-smoke-prairie-moon-nursery.html

Your gardening knowledge is superior to mine, but your inspiration pic is gorgeous. I have a small, new-to-me backyard that is a blank slate right now (it literally has only 4 things planted--a very large maple, grass, and 2 bushes I have yet to identify).

The prairie smoke is beautiful and seems well-suited to your vision (it seems available on the site, unless I'm reading it wrong). I think bluestem would be a nice contrast in color, and dropseed would be a nice contrast in form. Are you considering an additional blooming flower or shrub? I'd choose perhaps a later summer/early fall bloomer once the prairie smoke is done.

I have some yarrow that isn't doing too well where I have it, so that's an option. Also considering hyssop, borage, clover or some type of wild pea or vetch, thyme, anise or corriander, whichever I can get, and maybe eventually moving some narcissus that I have under another tree that doesn't appreciate them . . . Maybe some lemon balm I have a source for that . . . Those are all apple companions. That was the original plan. Just wanted to add some kind of spring bloomer that just jolts a bit of joy underneath when the apple tree is in blossom. I never thought of prairie smoke but I have had some success growing it under similar conditions. Need a lot to make an impact. Problem is, not available bare root, just seeds which would be best sown in fall. I might see it as a perennial somewhere this spring but it isn't common because it's a small plant and doesn't make a big splash in the garden. I have come to learn that most folks want splash . . . so the more subtle plants for the garden have to be specially procured . . .

I'm thinking eventually of adding a clethera shrub as I expand the bed, but probably not this year. Just going to do the apple and now is the time to establish ground cover around it, before it gets too big . . . which of course will be at least three years before it's big enough to make any type of impression. But we've had good luck with other small trees taking off . . . If it doesn't take I have to more options, sweetbay magnolia or mountain silverbell. I have to special order the apple from a place in CA, only place I was able to find this heirloom apple--James Grieve. They seem pretty confident on their trees though, and I have had luck with trees shipped all the way across country--if the are small and packed properly . . .

Edited to add that ajuga and muscaria are good for blue, usually found around here not too expensive. The pink is stumping me. Wild pinks and phlox would be the natural choice, but they are low to the ground . . . I am trying to think of something medium height . . . it's the spring blooming that is the kicker . . . I do see some pink wild geraniums . . . not my idea foliage but if I spread them amongst something grassier it might be a good contrast, like the photo above. There are also some pink coral bells that when planted en masse would be "foamy" like my inspiration photo. But again, their foliage is quite prominent. Astilbe would work but they bloom later . . .