Guidance on neophyte's native plant restoration garden
I have about a 2500 square foot patch of ground that I killed off with roundup in the spring of 2005. It had been partially dug up in the summer of 2004 for the installation of a new septic system and was mostly covered by weeds. About two weeks after the roundup, I planted a native widlflower and grass mix from a local source in Michigan. I wasn't real optimistic and was mostly ignorant and needless to say over the summer of 2005 I ended up with mostly two weeds that seemed to be non flowering. I trimmed down the patch in the fall.
This summer has yielded a much greater variety, with (1) many non-native wildflowers, (2) two natives in the mixture that I planted: black-eyed susans and yellow coneflower, (3) 1 native that I didn't plant: fleabane, (4) and then predominantly a variety of noxious weeds that I either can't identify as natives, or are clearly non-native (most don't seem to be flowering or obviously flowering).
So my question is, at this point, what would be the best method of getting a diverse selection of native flowers and grasses to become the primary constituent with the reduction in the non-natives? I'm open to any suggestions and am not really in a hurry. I just want the best approach that will yield the best results without huge costs and with the most efficient use of my labor. I suppose I'm fine with the work, I'd just like it not to be ignorantly counterproductive.
I've considered cutting it down later this summer and covering it with carpet and tarp (which I have plenty of) until fall, then pulling up the covering, slightly breaking up the soil with a spring rake and planting another mix.
The mixture I planted in 2005 is as follows:
Bergamot, Black-eyed Susan, Golden Alexander, Lanceleaf coreopsis, Large-flowered beardtongue, Partridge pea, Purple coneflower, Purple prairie clover, Rattlesnake master, Rough blazing star, Stiff goldenrod, Smooth penstemon, Spiderwort, Western sunflower, Yellow coneflower, Little bluestem, Side-oats grama and Prairie dropseed.