Just read your Aug 9 article re nutsedge. A greater concern of mine is how to control post emergent crab grass without killing existing lawn grass. Can you help?
Crabgrass has enjoyed a banner year. There are post-emergent crabgrass killers available, but as crabgrass is now at the end of its growth cycle, it would be difficult to kill it off. The plants are huge and have flowered and set seed, so the uptake of the post-emergent chemical would be minimal. The plants themselves will die when we have a hard freeze. Before then, hand pulling the plants to avoid them setting even more seed is an option. Yes, this is time consuming if you have a lot of crabgrass, but each plant can produce thousands of seeds!
Your best bet is to plan for next year. About April 1 or so (about the time the redbuds bloom) apply a pre-emergent crabgrass chemical. Maintaining a thick turf is important.
Hope this helps.
Carole-Johnson County Extension Master Gardener