Can you give any inexpensive non-chemical options as we prepare a 2 acre site for a charity Pumpkin Patch? (It has been dormant for almost 9 years)
For a two acre plot, covering with mulch will be a big task however, a thick layer of mulch could be applied to the field. This is much more labor intensive than spraying with an herbicide, but it certainly is better environmentally. You could use straw, plastic sheeting (more expensive), thick newspapers or sometimes the townships have leaf collections which produce good mulch--they might even deliver if they know your cause. After mulching, plant the seeds in rows and in openings in the mulch cover. The only alternative would be to weed the worst and most offensive weeds as they appear. The pumpkin plants themselves might squeeze out some of the weeds.