When can I introduce my new chicks to the older ones?

Yes, you can. Grower is perfect as long as you have oyster shell grit for the older chickens.
I have my 9 week old chicks with my 18 weeks old chicks. They've been together since the younger chicks were 4 weeks old. I'd recommend putting several feeding and watering stations in the coop though.

 

I try to wait till the chicks are at least ten weeks old. It is better if they are nearing the adults size. The more room you have for them to get away from the adults the younger they can be. Since they have seen each other for a while you could make an opening in the fence just big enough for the chicks to pass, but not the adults.

 

Put a small opening in the fence that separates them, big enough for the smaller birds to get thru but not the bigger ones. I did this by using another piece of fence with the corner bent up.

You might have to show the younger one how to get thru the opening at first. Then the youngers can go in and out of the opening to escape the olders. By the time the youngers won't fit they should be pretty well acclimated.

 

Did.......you......just.........s..s..s..say.....SNOW?!

 

Well, this is as a good a place as any to post my question, as well.

I need some advice on integrating my flock. My HUSBAND wanted to let our broody Cochin hatch some eggs, so we got some fertilized RIR eggs from a friend. We have 1 Cochin and 5 Red Stars. The Cochin is at the bottom of the pecking order.

Only one egg hatched so we put her and the newbie in the shop in a nursery/brooder. The first chick is now 8 weeks old.

Since there was only one, and we didn't have a broody hen anymore, he had his friend hatch us TWO more RIR's. They are now in the shop in the nursery/brooder and are 4 weeks old.

I want to introduce the 8 week old and Cochin mama back to the 5 Red Stars. I've been trying, but those Red Stars are aggressive. We have an open, fenced large run with a completely enclosed run inside of that, with the coop inside the enclosed run. The Red Stars like to sleep on a perch, outside in the locked run at night. So, I've been putting the 8 week old and the Cochin in the locked coop (door off automatic open).

Then, at 5am before I leave for work, we kick the Red Stars out of the enclosed run and open the door to the coop so mama and 8 week old can be safe inside the inner run and have access to the coop. But, they all are able to see each other and interact. It's been interesting, to say the least. This is a hassle. When can I introduce them? Is 8 weeks too young? Also, I guess I'll let the 4 week old live in the shop until they are almost full grown which will be in dead winter.

I really bombed this one. I need advice!

Thanks! Sorry I hijacked your thread.