Dahlias: what is LEAFY GALL? 

Thanks Brad for your kind comment. I hope you never see gall in the flesh!

Thanks! Kind of you to comment.

Thank you for your kind comment. I am sorry you have some Leafy Gall this season and hope you have a great season next year.

Hi Monica, yes other growers are reporting a high incidence this season here in the uk good luck with yours.

Thanks Yesid

Hi Josey, thanks for your question. As you probably know Leafy Gall caused by a bacterial infection, and this is thought to gain entry through wounds in the tuber's skin. Once inside it affects only meristematic tissue - the buds and early shoots, disrupting their growth pattern. The effects are seen as overgrowth and distortion of the shoots, where they emerge from the tuber. So the answer to your question is Yes it can be present in the tuber and there are no visible signs until growth starts. Once a tuber in infected there is no cure and it should be destroyed, together with some nearby soil to try to limit spread. Hope this helps,, and good luck with your growing.

Hi thanks for your question. If you take a close look at the crown after cutting the upper part of the plant away, you will see the typical proliferation of young shoots. A close look and an experienced eye is needed. Good luck with you growing!

Hi Catherine, Thanks for your very good question. I've looked and so far have not found any trials to give a science based answer, but I have formulated a "working" answer from my own experience and the published data. The short answer is "maybe". The longer answer is that the disease can of course recur in tubers from the same plant which appear normal on division as the organism is transmissible (and also can be present in the soil). But for bacterial infections the organism can be localized, and therefore healthy looking tubers may escape. Viruses are different in that they usually infect every cell in the plant, so there is no escape, plants must be destroyed. So in a practical way, my decision to discard or save a tuber is based on how precious the variety is. If it were an irreplaceable treasured plant then certainly plant up single tubers in isolation and keep fingers crossed. If it were an easily replaceable (eg commercial) tuber, I would discard and re-purchase new tubers. If anyone DOES know a definitively tested answer I would love to hear it too!

On the plant where you illustrated the gall growth the greater part of the plant ‘looked’ healthy. As a cancer can be cut out with a margin of healthy flesh, could you not have tried this as any eventual new growth might not show this infection?@@MoorfieldFarmFlowers