Yes need to attack them when flowering. If you neighbor has it and doesn’t do anything it’s gonna keep creepin.
They are tough little buggers.
Creeping Charlie/Jenny is a bane. I hate it, hate it, hate it. My neighbor does not do anything about his, most of his lawn is Creeping Charlie. His wife will not allow him to use herbicides, she believes it will harm their dogs. So I gave up on that side of my yard. The other side looks good. I will get gung ho about this again, but it will again be like flogging a dead horse. Spraying after it blooms will slow it, but will not kill or stop it. You need to apply the herbicide either early in the year before the leaves get really green and waxy, or later in the fall. Some believe, old timers mostly, that spraying a Borax/water mix on it a day before you apply the herbicide, speaking on already greened up, waxy leafed, flowering C.H., will disolve the wax on the leaves and allow the herbicide to enter the plant and do it’s thing. I have done this and had better results than not doing the Borax. Good luck.