Update: My Buddleia davidii has since been shovel pruned. I kept getting severe ifestations of Two Spotted Spider Mites. I tried to control them with a jet of water, but that didn't work. I tried to control them with foliar insecticide, but that didn't work either. The second year was more of the same, but the spider mites began to spread to other plants in my yard. That was when I shovel pruned the butterfly bushes. The spider mites are gone from my yard now and I'm still not sure why the Buddleia davidii in my yard had such a problem.

Thanks for the suggestions! We don't like grasses in the yard, especially after helping our neighbor get rid of some really, really invasive grass that Urban Gardener planted in their yard this past year. We have a lot of shrubs in the area already, and are looking for something more low-lying (less than 2"-8" tall) to fill in. I've never really had a thing for mondo grasses, but we all have our loves :) Between the three spreaders/clumpers above (veronica, epimediums, partridgeberry) we should be able to work something out to cover at least 60-70% of the area in question, which would mean 60-70% less weeding, and something to keep the ferns company during the winter when many of the other things have died back. I don't mind spending $$, I'm totally fine with that, but ... I don't want something that is a tiny 6" clump at full size, else we will be seriously spending a thousand dollars buying 200+ plants to fill the bed. Are the three aforementioned species relatively safe to plant near perrenials that die back down to the ground every year and re-sprout, or will they choke those out? If it is not safe, what kind of spacing should I be trying to maintain between these and other plants? (i.e. would the average spread diameter + 6" buffer be adequate?) I am normally really wary of non-native species, seems like most of the common ones are too invasive for my liking, which is why I had to ask. Search was turning up a ton of results, but I couldn't seem to refine it enough to find meaty info. Thanks again for the advice! BTW - Epimedium warleyense and versicolor flowers both look amazing! (see pics halfway down page)

Is this a true coastal environment such that the soil is sandy? If so, some consideration to that may be needed. If that strip between the neighbor is truly shady then neither grasses nor Ilex verticillata are appropriate (unless you don't mind a lack of blooms). For the ground cover on the shady path, consider Antennaria plantaginifolia . Amelanchier canadensis is a nice specimen tree. Does the area get afternoon sun? I'd also consider a native azalea if they are appropriate for your area or a Viburnum (some of them can be like a small tree).

Yeah, I was going to say that too. Why plant a non-native magnolia when the Sweetbay (Magnolia virginiana) is so nice? Also the Bay Laurels (Myrica) might work well too and I'm fairly certain several of them are native to your area. I have no Idea if it grows that far north, but fringe tree is another small (and fragrant!) tree that might work. Lastly, you might try one of the native witch hazels. There is a fall blooming and a spring blooming one (and the both bloom after/before almost anything else).