If near the boundary with neighbor you'd like a tree or two, consider River Birch. Native to the eastern United States USDA zones: 3 to 9 Water requirement: Moderate to wet soil; adapts to stream banks (as its common name implies) and poor soils. Light requirement: Full sun to partial shade Mature size: 40 to 70 feet tall. Benefits and tolerances: Fast-growing, disease-resistant choice for riparian.......

With a little night lighting possibly the neighbors wouldn't see as much of your fire circle. Would be nice when seen from your inside rooms at night [instead of the outdoor darkness] - as they grow, seen from upper level too.

Mediterranean Brick Courtyard · More Info

Ferns, sedges, japanese forest grass, lilly turf, rodgersia, ligularia, moneywort, lobelia, tirella.... (think foliage in a shady garden)

Ever sit under the deck? If not, what about the ferns under there, and to get some water as it drops down....a nice group of them...

4a in the middle of the state and 4b farther south... I have grown a hosta variety in some shade. Good website:

http://www.extension.umn.edu/garden/yard-garden/landscaping/best-plants-for-tough-sites/docs/08464-clay-soil.pdf

Look at red-twigged dogwood, nice in winter against snow [photo in link]:

http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/selecting-shrubs-for-minnesota-landscapes/

Why wouldn't ferns grow?

http://www.missouribotanicalgarden.org/Portals/0/Gardening/Gardening%20Help/Factsheets/Clay%20Soils%20-%20Annuals5.pdf

Maybe you need to add more compost/manure etc. if your soil is very poor.

Seems anything under the deck is less important than your lawn- if turning brown, or whatever, it could look mucky and not fresh and vibrant.

What are your main concerns? Fire pit should be safely out away from property line and deck -- does a home association need to mow, or you?

Was it red-twigged or yellow? I think they look great with snow.

I don't think I said it 'right' - I meant under the deck seems a lower priority....

There's lots of plants adapted to clay soil, joe pye and rudbeckia lacinata, cup plant and probably flowering raspberry, vernonia, blue flag iris....