Hi Everyone,
Every so often life history questions like this come up, and there are at least two online resources that are valuable for answering these kind of questions.  The first is the online version of Arthur Cleveland Bent's Life Histories of North American Birds, part of which can be found here: http://birdsbybent.com/contents.htm
For example Bent notes that an observation in Michigan had young in the nest as late as September 25th in the 1930's and 40's.
Another valuable resource that is worth investing in, especially if you are interested in bird biology beyond just field identification, is the Birds of North America OnLine: http://bna.birds.cornell.edu/bna/ 
While the BNA costs an annual subscription (or you get it free with a membership to the American Ornithologists' Union), it's well worth the investment especially since the life histories are updated by experts as new information and new research becomes available.
Content from the Birds of North America is used to produce Cornell's All About Birds website: http://www.allaboutbirds.org/
These two resources are the most detailed resources available about North America's avifauna. A similar resource is being developed for birds of Latin America: http://neotropical.birds.cornell.edu/portal/home
Hope this helps,
Casey Tucker
> Date: Sun, 18 Oct 2015 22:09:56 -0400
> From: [log in to unmask]
> Subject: Re: [Ohio-birds] goldfinch fledglings
> To: [log in to unmask]
> 
> I don't know much in the topic, but the gist of what I have heard is that goldfinches have a very late breeding season, in late August through September. I observed a downy goldfinch, unable to fly yet, on a fence around September 20th this year.
> 
> Gautam Apte
> 
> On Oct 18, 2015, at 9:48 PM, Barbara Zaas Partington <[log in to unmask]> wrote:
> 
> > I may not have paid attention in the past, but this year, i have watched, for the past week, multiple young goldfinches being fed by adult birds.  It seems very late for them to not yet be on their own.  
> > Or maybe they are just lazy and taking advantage of helicopter parenting?
> > 
> > Barb Partington
> > Geauga County
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