I have a garden section that gets sun from 3-6ish also in zone 5.

Hosta, anemone sylvestris, tradescantia, toad lily, veronica, bearded iris, foxglove are visible here. The weird white discoloration on my hosta is diatomacious earth--I had a slug scare and dusted all my hostas.

I also have some daylilies planted in this area. Other plants i have include helleborus, heuchera, tiarella, columbine, delphinium and campanula.

If your soil is good and moisture is adequate, it may partially be that the plants need a bit more time to get established. My daylilies and hostas do not seem to fill in until their second or third year. I have neighbors with hostas in full sun. As long as they get enough moisture they seem to do fine in sun here, SE Iowa.

Bletilla, Japanese anemones, cardinal flower (if it isn't dry), spigelia, Siberian iris, woodland phlox (stolonifera and divaricata), crested iris, green and gold (chrysogonum), foxglove. Most sun stuff can probably manage there but may not flower heavily.

most everything should do well there ...

but do understand.. that great expectations.. is one of the hardest hosta to grow.. and a vast majority of them simply fail ... so if that happens.. its the plants fault.. not yours ...

i would suggest.. a nice thick layer of mulch.. will take you a long way further.. rather than plant selection ..

your direct sun.. is the heat of the day.. mulch will retard weed growth.. retain moisture.. and COOL THE SOIL ...

and in accomplishing that.. you may find most anything will thrive in that spot ....

also keep in mind.. the bigger the flower.. the more sun things need ... so with your limited hours of direct sun.. you might not grow giant hybrid roses.. etc ...

mulch baby.. mulch ...

good luck

ken

Hardy geraniums would be perfect for that spot! So would verbena!

Got some Delphinium, Astilbe and mulch... Gonna leave it for awhile and see how things do... Thanks for all the advice and suggestions!