When is the best time to dig up Iris's? Mine have become very dense and clumped together and probably too deep. I would like to dig them up, separate, trim and replant. Fall or spring?
If you have bearded irises, the best time to transplant them is in the summer, June through July. https://extension.umd.edu/hgic/dividing-iris
If you have Siberian irises, you can transplant them in the fall or spring, but fall is preferable. It can take them a year or longer to re-establish after transplanting.