Unless you are opposed for religious reasons, this is exactly the type of situation that roundup was invented for. One sprayed on dose and you can start seeding the next day. IMO, it would be more environmentally friendly than slowly solarizing a big area. You save all the benefitial insects and microbes and you can plant your wildflower crop immediately. The long term impact of a 1 time application of roundup is just about zero. All that plastic you buy to cover that much area will be with us for thousands of years. If you are absolutely opposed to roundup, you might try vinegar on a hot day. It will probably take a couple tries, but it does kill cool season grass.

and i've seen i. cristata growing in areas in digs that nothing else would. it's a tough little booger. cyclamens do like the dry shade, but set the snooze for 10 years if you want to see much spread- :). they are slooooow. i'm just now getting some babies 10+ years after i planted my first ones. you know, most folks consider violets weeds, but they can deal with dry shade well. as can epimediums. and i really hesitate to mention that periwinkle does just fine with dry shade once established (and i have lots if you want some- lol). did anyone mention hellebores? they don't seem to suffer when it gets really dry. up at camp in PA, bracken fern spreads really well in the dry shade. not sure where to tell you to get it here, but...

Hi Scott and Ianna - thanks for your replies. Scott, I practically LIVE on the Grow Native website and have utelized the conservation dept. info at every turn for the last three years. smile. They are really incredible - so lucky!! I am definitely going to use the MO primrose and pussytoes (which I have growing in my prairie field); I already have the rudbekias and echinaceas going in the perennial herb/flower bed on the periphery of this location as well as wild lavender hyssop and some other natives such as tickseed coreopsis and fire pink (catchfly). I'd love to get my hands on some liatris but I think they're difficult from seed and my budjet is busted already! smile. As for the thyme, I've decided against it for a few reasons - mostly the bees (although I'm pretty sure wooly thyme would grow at this site because my creeping thyme near the same area grows gangbusters - and - my drainage here is too darn good). I've settled on arranging some large rocks naturally around my oaks, filling the niches with soil and planting tough but showy specimen plants such as epimediums, hellbores, coreopsis, heuchera and others that look natural and somewhat casual and filling the pathways with something like buffalo grass (not sure on that, might end up being river gravel). Does anyone know if you can grow epimediums from seed???

Oakleif, The state line isn't going change a lot of the plants you can select from. You can go to the Grow Native website for lots of info and apply it where you find suitable for your own landscape. :) Here is a link that might be useful: Grow Native