To prevent crabgrass in my lawn I use products with Dithiopyr (brand name Dimension). You can find multiple products with Dithiopyr, but this year I'm using Jonathan Green Green-Up with Crabgrass Preventer. You can see the Dithiopry under active ingredients. It will...

The two common grassy weeds I see in my lawn are poa annua (annual bluegrass) and poa trivialis (rough bluegrass). You can see poa trivialis as the fast growing light green grass in the picture above. The leaves are broad and tapering into a sheath, and the stems feel...