So, a quick pix with the iPad and sent off to OSU Extension and Melisa Fery came back with the answer - yellow glandweed, either spray or mow but get rid of it before it goes to seed. So we once again hooked up the big brushhog to Really Big Orange and off I went yesterday. Got thru 3/4 of the big north pasture where the infestation is the worst and tomorrow I'll finish it up.
Hope we got it soon enough. If not, we'll know for next year and hit it earlier
All those little spikes of green and yellow are glandweed. This was an area that didn't have a lot, compared to others
Because it was just such a pretty shot