I sprayed with 24D/quinclorac and then we had unexpected heavy rain about 8 hours later. I thought the spray was wasted so I planned to spray again in a few days since we had rain in the forecast for a few more days. The next day, I threw down a double dose of milorganite in between the storms. The day after that, I went out to check on the lawn and I saw that the broadleaf weeds were shriveling and the crabgrass turned brownish/reddish and some had even shriveled up and died. Not sure if the fertilizer and rain helped the plants take in the herbicides quicker, but when I sprayed 24D earlier in the season without fertilizing, it took about 2 weeks for the weeds to show signs of dying. This time, it took a couple of days.