How many broody days until new chicks can be put under hen?

[Lyranonamous]

I apologize if this question has been asked but I didn't quite know how to phrase the question to search for the answer.

I have a broody Australorp who raised chicks for me last year. She is a great mom and beginning to go broody again.
How many days does she need to be in the "broody mood" and sitting tight until I can put chicks under her?
I realized chicks would normally hatch in about 3 weeks but would she know if I put chicks under her in 2 weeks? 6 weeks?
Last year I didn't pay attention to how long she was broody before putting chicks under her so it could have been 3 weeks or it could have been a lot longer......

I'm asking because I might be able to get Speckled Sussex chicks from Agway the week of June 6.

I have been otherwise unable to find SS chicks. Our local hatchery is closing. If anyone knows where to find good quality SS chicks I'd love to know. I'm having a hard time finding them.

 

[sourland]

In my experience the closer to 21 days or longer the more readily a hen accepts chicks. Experienced mothers are generally more flexible and will accept chicks somewhat earlier.

 

[Lyranonamous]

thanks Sourland. I will wait a few weeks.

 

[Lyranonamous]

One follow up question. If we buy chicks from Agway they will be a few days old when we get them home. Would we have a better chance of success with day old chicks sent through them mail? Agway has SS this week, but we are on a waiting list. So if someone doesn't claim their chicks by Sunday we can have them. I think that would make the chicks several days old because they have already arrived at the store. Or am I missing something.
Would this be more risky than day old chicks? She was a good mom to the mail order chicks last summer.

 

[lazy gardener]

The issue with older chicks is that they may not bond to the Mama.