Having worked for several years to establish a matrix of plants that will be at least partly self-sustaining, I can see some progress this spring. At this stage, I'm still keeping pretty much anything that covers the ground and prevents random germination from the seed bank.
Thanks to Noel Kingsbury's books, I now know I'm trying to orchestrate a bunch of competitive perennials, stress tolerators, and those opportunistic ruderals, plants that take advantage of any open ground in the early stages of a planting, where they thrive until extinguished by larger or more competitive neighbors.
The picture below is of one of several Filipendula rubra 'Venusta' that have settled in well and are slowly spreading. I'd judge these to be moderate competitors; they are slowly covering more ground, but they don't self-seed at all.
Next is another sample of a matrix planting, primarily Petasites hybridus, native Equisetum arvense, native Lysimachia nummularia, and at the far edge, Carex muskingumensis, Darmera peltata, cimicifuga (actea), and thalictrum. The equisetum, though highly invasive and a competitor par excellence, will wither away in a month or so, leaving room for a really disgusting ruderal, Japanese stilt grass (Microstegium vimineum), to intrude.
The vertical wands rising from the petasites are flowers, which you can see more clearly in the next photo.
The next two photos show views turning clockwise about 150 degrees.
The more "finished" matrix above contrasts markedly with another garden view below. Here is where the filipendula I opened with grows, along with other large wet prairie perennials such as Eupatorium purpureum (Joe Pye Weed), Liatris pyncnostachya, Rudbeckia maxima, assorted wetland irises, sanguisorbas, miscanthus, panicums, and other plants too numerous to list. Obviously there are no early perennials to make an attractive matrix planting here. This area won't reach its potential until July.
Here is where I need to develop spring plantings that will give interest and good coverage early in the season, then disappear, or at least tolerate shade cast by the larger perennials later in the season (spreading stress tolerators is what I need). More bulbs (stress tolerators) can certainly help, especially daffodils. Native persicarias especially like this area as the season progresses, so some early persicarias, such as Persicaria bistorta 'Superba', may be helpful. And, of course, a blanket of astilbes would give both color and interesting, long-lasting structure.
I'm open to suggestions.