Carpinus caroliniana is not a "glamor" tree, so many nurseries don't stock it. Blooms are insignificant, I don't think any have been bred for their sometimes gorgeous fall colors. They don't grow fast, and the world is into instant. Tonight I heard a program talking about trees that fall onto houses, power lines, etc. They spoke to a tree expert from NH who specifically mentioned C.caroliniana as a desirable tree to plant. And I had to love her when she mentioned avoiding fast growing trees that provide instant gratification and fall when the wind blows. She was also decidedly cool to conifers, mentioning White Pine as brittle and prone to breakage. Another point was that any tree within 15 ft of a house was too close.

as i'm thinking about your question I'm imagining the space, and realizing that 3' x 8' is about the size of a sofa.I'm thinking you need bold visuals- rather than small fussy foliage-to play off the all-green back wall and to be seen across a distance from the walkway. I am thinking a small variegated weigela, which blooms a long time,along with a small deep purple presence- a patch of purple perilla or a mini dk. ppl.weigela or your ppl.heuchera idea.A 3-season patch of Yellow (that would also play nicely w/ the rozanne) could be provided by carex Bowles Golden or Hakonechloa or golden Tradescantia____ which would provide you some spiky form in the midst of mounded shapes.Also helpful for shape and color and height variety- would be the tall yellow flower spires of kirengeshoma and the ppl. foliage w/ white floral spires of cimicifiga black negligee. you might like 1 or 2 peonies next to your iris. best, mindy

The only one on your list that will reach near 40' (in your lifetime) would be the Honeylocust. Fall color won't be that great on most honeylocust. Amur Chokecherry (like most Prunus) is short-lived in the Midwest and is a small tree to begin with. Both Ironwood and Carpinus are nice but will not approach 40' and will be slow growing. Tupelo would meet your size requirements but you would want to ensure an acidic pH and damp soil (also many cultivars are not fully hardy in zone 5). Paperbark Maple is another great tree but is quite slow growing. $1000 for a 10' tree is ridiculous unless the branching/top is very well-developed. Other options include: Crimson Sunset Maple (medium growth rate) Redpointe Maple (fast growth rate) Fall Fiesta Sugar Maple (fast growth rate) State Street Maple (medium to fast growth rate) Kentucky Coffeetree (starts out a little slow but grows quickly after established) Butterflies Magnolia (would be a little slower growing but unique) River Birch (fast growing) Swamp White Oak or Heritage Oak (may grow over 40' but will be quite a while) American Persimmon (will grow quickly after established and is unique) Most of these will be available from local retailers or wholesalers. Keep in mind mature sizes are always approximate. It all depends on the site, care, and other factors how quickly a tree will grow and when its growth rate will slow as it begins to enter maturity. No tree will grow to 40' and stop. I would hope you could get (3) 10' trees for $1,000.00. Good luck!

Woodnative, that's a nice spot you've put together. My Chionanthus are still a few weeks away from flowering, but you've reminded me what I have to look forward to. In these parts, Carpinus caroliniana is an understory tree with a strong preference for moist soils. They can handle more sun, but moist soil is a consistent. They will also look much different in full sun than in their natural shady conditions. Personally, I think they look better when grown in shade. The canopy is more open and with horizontal branching. I've got two growing here, both of which I've sited at the woodland edge. To get a real appreciation for this tree you need to venture into a moist woodland.