Hm, no idea frankly
@OldGardener . I never dug up any of the glads.
I'd just go and visit my mother for a week every few months, as we were living in Salt Lake City (or here in FL)as she declined. I'd spend the week messing with her garden of course, and for a while I'd plant new glads, but once I stopped the ones in the rose bed kept blooming for at least 5 years without being lifted or divided.
That would indicate to me that it's weather-related. That bed was at least a zone warmer than the rest of her garden. It was also the only area I would consistently amend with compost in spring, and mulch in fall. Otherwise the only gardening that was done was lawn mowing and a regular spring cleanup by her landscape guy.
