So do I just… let them outside?

Hi all, newish chicken owner and very new chick owner here 😅 We got chicks five weeks ago and are starting to plan how to introduce them to our existing flock and transition them out of the brooder and outside! We have 8 mature hens and six chicks.

I understand you cannot just merge the groups together, it needs to happen slowly. We have a large backyard and part of it is fenced off for the chickens. I’m thinking that I will keep the hens in this area and let the chicks in the other part. They can see each other through the wire fence for a few weeks.

My question is more so about just letting the chicks outside in general, it feels a little nerve wracking! We’ve taken them outside for a couple short stints on warm sunny days but we’ve kept them contained in an empty raised garden bed box. At a certain point do we just let them free range? How does this normally happen? 😅