Hi,

I think most plants will rot in these conditions. You probably need to build the area up with some dirt and/or rocks, something to level out the ground. Then you have lots more options, and you wont be constantly replacing plants that dont make it. Just my opinion.

Jen

The little moneywort, Lysmachia nummelaria, can tolerate being underwater for a while and would probably thrive. A highly invasive plant, but Houtonia is worse. In time, you may find you need a sump-pump under your house. The hay-scented fern might tolerate full sun with enough water.

Sounds like my water garden- or what I call my watergarden! It catches the run off from the roof. Because the water crashes down there I don't put anything in the crash zone- however I have planted the edges. It is wet for days after a rain but also dries on top.

Here's what is happy there- these might be too tall for your needs.
Clustered bell flower ( campanula)
golden creeping jenny (lysimachia)
variegated lysimachia called golden alexander ( I've seen this one in a pond too)
bloody dock ( might have died or still dormant- Ist try on that one)
variegated japanese iris- new- not tested
laevevvia japanese iris- new not tested and badly mispelled!

not a groundcover but happy :
iris pseudacorus trying the variegated form there which is shorter now.
siberian iris ( can be a pond marginal)
and near the wet spot but not in-
bulb camassia

Tropicals I might move out there after digging it deeper and when warmer-
Cyperus papyrus
umbella papyrus ( can take it a bit drier and shorter than the cyperus papyrus)

Hows that grab yah?
karen zone 5 with 40 inches rain per year.