My flock of 4 are allowed to free-range in the back yard any time they want. I've noticed a huge increase in dandilions over the past couple of years, and am now tired of having more dandilions than grass. So I want to apply some Weed & Feed to my backyard. However, I'm really concerned about the impact on my hens. I know that they like to eat anything they can get down their throats, so I'm planning on locking them up in their pen while I spread the weed & feed. However, I want to let them out as soon as possible, since I hate locking them up. Any suggestions on how soon I can let them free-range after treating my yard? I tried the non-chemical method of popping the dandilions out with with a gardening fork, but after filling a five-gallon bucket & not noticing a dent, I got a bit discouraged. I'm also sure that my lawn could use some fertilizer (more than random chicken droppings everywhere ), since my lawn hasn't been fertilized in over 5 years now.