Introducing new chicks to year old chickens

here is how I have been doing it,   I have a large run  80ft x 90ft. I have a seperate pen and run within this. the little ones go in this for awhile so they can all see each other but can not get to each other. after they seem comfortable with each other I will let them mingle with supervision after a week or so of this they seem to naturally follow the older birds to the big house...I know not everyone has a run this size, but this seems to work well for me.

We'll be in the same spot  come April. We plan on making a mini coop from pallets in the run so they can see but not touch. I think by 12-14 weeks old we will try to have the full "meet and greet!"

This is my second season too....I have been hatching my own now. What I did just a couple weeks ago was, put a cage in the coop with the younger ones in it. This way they all could get use to seeing each other and hearing each other. The ones I'm doing this with are 9 weeks old, they will be the larger breed and right now are as big as my smalles full grown bantam. Saturday I decided to let them out, it was getting too crowded and they were in there for two weeks. At first it looked like a big gang fight but the little ones flew out of the big pile and squawked some and that was it, they are all getting along, Once in awhile one will get in the way of the older ones, it pecks and off runs the little guy. I thought I was in for some major fighting and blood bath, I dont know if I got lucky or not but it all worked out well!

Good luck

i would introduce them in the night when the others are calm thats what i do.

My problem is the big chickens wont let the little chickens in the coop at night.  The are free range chickens but the littler chickens sleep on the deck at night and its starting to create a problem for as far as mess goes. I have stuck them in the coop at night a couple times but they dont return the next night. My old chickens are 3 and the new ones are now 16 weeks.

I am about to do this also for the second year.

Last year, I had two batches of chicks about 8 weeks apart, so it wasn't like introducing full adults with babies, but we still had to go through the Intro process, as I raised them completely separately.  I read some wonderful advice on this forum, which I followed and it worked great.  Add some large colorful children's toys to the coop/run at the same time you let the ages mix.  The larger birds are distracted by and interested in the toys, and it adds places to hide for the little chicks. 

I plan on doing this again, as well as letting them meet through a cage/crate for a while, etc. as others have been saying.

Good luck to you (and to me in a week or so!)