Hi Jean
In the early Fall after the foliage has started to turn yellow.
-Helen

This spring we had to remove some lillies that were in barrels, they were up 2 to 4 inches each...we pulled several babies off the very big clump of bulbs and scattered them in groups around the yard...they all continued to grow and are now blooming. Since we are landscaping a new yard, we also bought 15 lillie bulbs and only about half of them came up, none of them are very big and none are offering to bloom, but may not be due to do so yet. Two weeks ago we found we were going to have to move from the location of the whiskey barrel lillies, and since we didn't own the barrels, dug the lillies up with lots of surrounding dirt and moved them. The "mother" lilly was almost 3 feet tall. It transplanted well and is budding now. I don't know the names of the lillies but they are asiatic or oriental...I can't tell the difference.