How old should my chickens be when I clip their wings to keep them flying out of their yard.
Old enough to have their adult feathers.
The first thing a chick grows is those darned long, strong wing feathers, and since they don't have any weight, they are all horsepower and can fly like freakin' eagles. This coupled with those nice strong legs to jump with, makes the little stinkers able to get into trouble at the drop of a hat.
I really wouldn't clip the juvenile feathers if you can avoid it, just keep them penned until they get some more weight on them. Once they get their adult feathers, usually they've learned where they live and don't take to flying so much, especially heavy breeds. Banties are more apt to fly up into trees and such, especially to roost.
Make sure you clip their wings correctly, if you do clip:
This page is aimed at parrots, but a wing is a wing. :)
Thanks everyone. I thought they were old enough to clip but wasn't sure. Their home is 1/4acre - they share it with roses - with their coop in the middle of it. Besides being well fenced, most of the fence has 5/6/7ft and bigger roses growing along the fence so they really don't show any inclination to wander but I figureed I should clip just to be on the safe side. When the dogs follow me into the "bird" area they aren't interested but I wouldn't want to tempt them with a wild bird out in the rest of the yard. Besides some of my neighbors would figure it was a square meal free for the taking.