I have never planted grass seed before, and I have no existing lawn, just a thick shaggy carpet of seasonal weeds that, thankfully, my feather babies find very appetizing. I bought Scott's Turfbuilder Dense Shade Mix (fescue of various heights) back in spring, but due to illness and bad weather could not plant it. I want to plant it in the new chicken yard (which is fairly bare from construction damage) while waiting for the fence to be installed. How long should I wait for it to establish a root system before introducing the chickens to their new salad bar? Like I said, it's all fescue, which I understand is an aggressive rooter. The soil is Ultisol (dense red clay). Thank you!