It frost seeded itself.One thing to keep in mind with all NWSG is that it can get so thick that young birds and most animals may quit using as they can't travel and can even die.This is the reason that sometimes light discing is recommended and another reason I like ares that are thinner weeds or shrub plots.I have drilled quite a few acres and frost seeded some and I really think frost seeded establishes quicker.I broadcast mine on as bare of soil that I can right before a snow.