During the many years when we planted only in the spring, it was usually around the middle of September when we'd be digging them. If your leaves are just beginning to show some yellow, keep a close eye on the lower ones. They may change rapidly now with the shorter days. If the lower 2 or 3 start to look poorly, dig them up. Cure for about 2 weeks and try to get them back into the ground by early October.

Martin