I have used Preen, a pre-emergent for weeds in my flower beds. It is in a granular form. I left it on for several days and kept my chickens inside. I also waited until we had some rain to get the granuals to dissolve. I don't have a hose long enough to reach all of my beds, so I can't hose it all in. I was just wondering if anyone knows if chickens will try to eat granulated chemicals like lawn fertilizers and pre-emergents. I've never used any lawn fertilizers, but I may in the future and want to know how long I should keep my chickens off of the lawn? I'm really concerned about the Preen though, because I need it to suppress my weeds and if my chickens have eaten it then I'm in big trouble!