I have about 4 ac tilled up and limed. I was plannning on planting a clover plot in mid summer in NE PA. It's been @ 3 weeks since I used round up. Do you think I should re-till the ground or re-spray with round-up if there is any signs of new growth.

i would retill. it's cheaper. plus you'll bring dormant seeds up to the surface again, and when those start to germinate you can retill or spray roundup again.

i'm taking a stab with this statement, but i would speculate that your last weed/grass control procedure before planting should be roundup. all prior ones should be tillage.

Either spray or till the new growth of weeds. Tilling will dowhat psandhu said. I see no advantages of spraying Roundup prior to planting if you are going to constantly rework the ground every 2-4 weeks. The only exception would be if you are going to notill or broadcast the cloverwithout covering it. Neither is too likely for aFallfood plot.