It's rewarding to observe this process of assimilation, and very gratifying to see that moment when the new crew has the confidence to finally stand up to the original crew and take their places in the flock. This usually happens between two and three weeks after they been introduced.
My integration is taking way longer than 3 weeks but I suspect it would have gone smoother if my RIR hen wasn't such a relentless bully to the pullets. I think if she were out of the mix 2-3 weeks may have been realistic.
People way more experienced than I have given great advice here but I'll give you an idea that helped us out when we first introduced our pullets to our existing flock. We built a small table about 2.5 feet tall and put it in the run with a separate feeder on it. What ended up happening is that my hens spend almost all of their time on the floor of the run and the pullets spend all of their time on that table or in the coop where there is a separate waterer. In all I have 2 water buckets and 3 feeders for 6 chickens. Overkill? Maybe.....but it has worked like a charm to not only have multiple feeders and waterers but also different vertical spaces where the pullets can relax a little and not have to keep a constant eye out for an attack. It was either @aart or @azygous who gave me this idea and it was a lifesaver.
