When to start feeding seeds?

[HennaRose]

My current flock is about three months old and I started giving them an organic seed mixture last week when their starter crumbles ran out. My current recipe needs a little tweaking, but here's what my big girls are getting right now:
whole oats
red wheat
buckwheat
sunflower seeds
millet
split peas
lentils
flax seeds
sesame seeds
kelp leaves (granules were impossible to find locally)

They also get at least a bucketful of weeds, green leaves, and grass every day. Bugs and worms occasionally, but they don't free-range because of restrictions where I live. This summer I'll have the big garden area fenced off and they'll have free access to that until it's time to start the fall planting. They have access to grit and fresh, clean water at all times too.

I'm getting a new batch of chicks in August and had planned to start them on crumbles, but I would like to know how soon I can start giving them the seed mixture.

 

[Den in Penn]

Some of the things in your mix are large for chicks. So I would hold off on the whole seeds until they are a round eight to ten weeks. Even then I think I would give them access to starter to assure they get all the nutrients they need for a few more weeks.

 

[1muttsfan]

I would recommend even older, 16 weeks or so, and closer to full-sized. You could start them at 8 weeks on some of the smaller stuff, but the majority of their diet should be a complete ration to ensure they receive the protein, nutrients, and proper calcium to phosphorus ration they need to grow correctly. Make sure to offer granite grit if you start to feed seeds.