I use pre-emergent in the spring. This spring I did one application of Weed B Gon CCO. I don't have many weeds and now I just pick them out when I notice them. I especially don't like violets and wood sorrell, violets because if they get big and seed, just one violet can propogate hundreds of violets, wood sorrell because it makes mats. Clover, I leave alone, as it seems to coexist peaceably with grass. There are other isolated weeds I leave, like some blackeyed Susans that have sprung up. If I found any crabgrass (haven't seen any except in the vegetable patch), that would get pulled immediately. Do you all have weeds you that you don't mind or that have to come out ASAP? Or do you treat all weeds equally as enemies? Which are tolerable, which are not?