Not sure where you are at Cantillon, but I am in the Pacific NW, zone 8. I agree that the standing puddles are worse on left-in-ground dahlias than freezing weather. Advice from a local grower was to dig up half of each plant for winter storage (as a backup) and leave half in ground. I typically just left mine in-ground and hoped for the best. Some years I am luckier than others. I'm currently down to one NOID plant and am considering starting over next spring with actual named cultivars so I know who's who. They are such a welcome spot of color in the late summer and fall. Here's who I fondly call Last Man Standing:
