I dug up my dahlia tubers and the tubers have bumps on them. I have never seen these before on my tubers. Is this a fungus or disease? What should I do?
Certified GKH Gardening Expert
I am not sure what these bumps are. They may be normal swellings called lenticels that can appear in wet weather. Or, they could be caused by nematodes:
I don't think it is any more serious disease, like crown gall.