Plantago majus..common plaintain I thought but after the size description, I'm lost..lol. Can it be some sort of runaway tobacco plant..maybe some variety of milkweed? It'll be interesting for someone to nail this monster down!
dave, are the leaves kinda fuzzy? almost like lamb's ear? if so, mullein...a sacred plant around here...heap big medicine. They are beautiful plants and can get quite huge! From the center it will send out a tall flower head, like a spike, that will be covered w/small yellow flowers. I'd mow around it if I were you. (I considered them "sentrys" that watch over Ma Earth.) (have any up your way patty?)