Our elderberries were done by the beginning of September, but they are a wild version and not a cultivar, so it is possible that some places may still have some to pick.
Consider planting your own if you want a reliable source. We planted only one or two plants a few years ago and now we have a thicket that threatens to take over our driveway. We bought ours at the North American Native Plant Sale which occurs usually the first weekend in May in Markham, but I'm sure there are other sources.
Yes, I had found that. We're playing phone tag... the proprietor left me a less than helpful message, simply saying that they didn't have any right now (no indication of whether I'm too early or too late). Hopefully she'll get back to my second message...
Any other options out there?