I'm in zone eight and the dahlias that I have planted don't seem to come back for more than three or four years at the longest before they disappear.

Several cultivars didn't even put in an appearance for the second year. I think they were part of the Karma series of cultivars.

I think 'Winnie the Pooh' is the cultivar that came back the longest.

Is this normal, or is something maybe eating the tubers?