When can I let my new chicks go in the same spance like my big ones.....

[Gypsygirl]

Good Morning everybody. I have a new question, my baby Orpingtons are now outside for 2 wks. with my old chickens. I did separated them so they can see each other and everyday my young ones who are almost 10 wks. old are in with the old ones. My old chickens have not done anything to my young ones. So, my question is when do you guys think I can take down the separation fence so they can intermingle with one another. I hope you can help me. Oh, I am from NC and love it here. Hope to hear from you folks soon. Thank you in advance for your help.