Ive recently come across a unique method using three applications of herbicide namely round-up. Open an area up in the woods 1/8 acre to 1/4 acre with a chain saw and make a brush pile in the center or where ever convenient. Dont worry about the stumps or larger logs that cant be moved. Spray round up the end of may, the end of June and again in mid September. Then the next spring in early to mid march frost seed on top of the snow a clover mix. Also spread 200 pounds/acre of fertilizer in the plot and while your at it also spread 200 pounds/acre of fertilizer in the surrounding woods. I know this doesn' t help for this spring but if you really dont want to wait for next spring I' d try the three applications and maybe bump up the last roundup application to the first of Sept. and try something like no plow a week to ten days after the last application. Then come back with a perennial mix in early march. Make sure you do a soil sample for the plot and if the ph is off you may have to use some pelletized lime on the site which could be a real pain in the rear but is well worth the effort. This has been done for several seasons by a guy in Mid-Michigan with good results so I plan to give it a try this year in a few kill plots located in the woods.