With the heat and humidity of this summer, our cool-season grasses continue to thin making it one of the better years in recent memory for crabgrass and nutsedge. In Lafayette, we’ve had 50 days of temperatures higher than 85F, 18 of which were over 90F. Maximum photosynthesis and shoot growth of cool-season grasses occur between 70F and 80F. Soil temperatures were also well into the 80’s, but root growth of cool-season grasses ceases at temperatures above 70F. High air and soil temperatures causing unhealthy and thinning grass plants, opens up areas in the turf for weeds to germinate. Unfortunately, there is nothing that should be done with these weeds now because they are too mature and are near the end of their lifecycle for the year. The best advice for most situations is to live with nutsedge and crabgrass until the first frost in (hopefully) a few weeks.