What time of the year would you start a new flock?

Iddy biddy's are always fun. I do it whenever I can.

Spring or summer, they get out of the brooder quicker

Always after the temps have stabilized and I don't have to wory about cold nights. Fuzzies don't handle clilly weather well! It is much easier to have them outside as well, less clean up;)

We started our flock in March two years ago and added more day old chicks this past March. Eva and I would like to stagger our flocks spring and fall but no stores have baby chicks in the fall around here.

Spring flocks are good if you keep them in a brooder box in the house,their feathers come on just as it's getting warm enough to put them out to the grow-out coop. If you have a secure place for them outside(garage/barn/brooder coop) a fall flock helps to stagger egg production which helps when culling older hens.

I started 2 years ago in early September- I hadn't planned or thought about it in advance, but it was a good time to start: the chicks (Easter eggers) were feathered out and ready to go into the coop before it got too cold (I'm in NJ). they matured during the short days and started to lay in February as the day light hours lengthened.

If starting with day olds?   March or September.  Each work well and both have some unique advantages.  11-1-11 doesn't work for me.  We are too far north.  For you?

Steinway you can search around and find older chicks sometimes but I really prefer day-old chicks. They are less likely to carry disease and seem to adapt to you better as pets. We brought in chicks once that were around 16 weeks old and I'll never do that again. We did the quarrentine and introductions just like you should but they never adapted to us or the rest of the flock. We ended up finding them another home.

You may have a different result, but that was our experience.

My preference in this area--upstate NY--is to start with day-olds no earlier than the end of April--actually May is better.  The weather is settled enough so shipping is no problem and with the warming temperatures the chicks are out of the brooder very quickly--should there be power outages they don't suffer either.   This means they are fully feathered and can gradually acclimate themselves to the coming of cold weather once the fall arrives.  Also they will begin laying in September in time for the baking season.