Over the years now and then I'll have one of these short stalks appear. They ususally don't re-occur in succeeding years though. Not sure what causes it. Have they had normal stalks in past years? I'm sure they will be ok next year. Sometims one will appear in a clump, and the rest will be fine. I had Ginger Ice send up a short stalk one fall, and I don't think it's a rebloomer, think it was just an anomaly, as it hasn't happened since. If you have a lot of them, I'd think there might some weather related issue maybe.
