A dry and hot summer in 2012 revealed the pervasiveness of herbicide resistant weeds in our row crop systems. Weeds were more visible, especially in soybeans, as stressed crops were reduced in height. I noticed marestail, water hemp and lambsquarters in fields treated multiple times with glyphosate. These are not missed applications or weed escapes but herbicide resistant weeds. Marestail, or horse weed, was most often observed, as it is adapted to grow and develop in heat and drought stress, better than the crop.