The prairie flowers in the dry area you mentioned often live with grasses - maybe the meadow/prairie forum would have a good suggestion on a companion grasses (off hand I'm guessing any good native prairie grass mix designed for your area of the country would work). Some of the plants you already have are some of the more aggressive natives so they will certainly fill in some space on their over time (especially the goldenrod). Some native violets might work in the dry area too but I'm not sure. For the wetter bed you might try some of the standard woodland natives like bloodroot, ginger, canada anemone (also supposed to be aggressive), virginia waterleaf and maybe some jack in the pupits.

Those are all pretty tall plants you've got growing. In the moist spot wild ginger (asarum canadense) or foamflower (tiarella cordifolia) or heuchera americana would be short additions. Others might be heart-leaved alexanders (zizia aptera) or maybe wood poppies (stylophorum diphyllum) or wood phlox (phlox divaricata). Or the anemone canadense noted above. Both the poppies and the anemone may spread.

Jason,

Near my house is a restored prairie where NE aster has grown in quite thick in the moist locations. It may just need some more time to establish. I can also mentioned that yellow ironweed(Verbesina alternifolia) will grow in thickly in moist areas. Carolina Rose will also grow in moist soil and may add some interest but won't fill in much space unfortunately but the pretty blooms would be a nice touch I think.

Thanks all for the input. bob64, I'd love to use violets but this is in my front yard and I'm afraid the neighbors will disapprove. davidl, I like the idea of foamflower and wild ginger. I suppose wild geranium might work as well. Strangely, golden alexander is not a short plant in my yard. It grows to almost 4', my wife calls it the golden alexander that ate Chicago. midwesternerr, the moist bed is just two years old, so your point is well taken. I tend to be way too impatient, though.

Thanks again for the feedback and happy new year.

jasonkay wrote-I'd love to use violets but this is in my front yard and I'm afraid the neighbors will disapprove.-

Do your neighbors ask for your approval before they plant invasive exotics?

Actually, the only invasives in my neighbors' yards are some shrubs they inherited. In fact, they have been pretty cooperative about my removing invasives from the hedges between our yards. As a result, I've been able to get rid of some buckthorn, shrub honeysuckles, and young siberian elms.

I live in an older suburb of smaller houses on 1/4 acre lots. My yard really stands out and the neighbors' reactions have ranged from tolerant to enthusiastic. When I dig a new bed or plant native shrubs I try to talk to my immediate neighbors about it to let them know what I am doing. To maintain goodwill, I'm reluctant to plant things in the front yard that will make them concerned about seeding into their yards.

This approach has worked fairly well for me.