[Ethel]

What is this stuff on my dahlia tuber? It looks like chopped walnuts. Is it some kind of disease? Just wondering if I should throw this plant away of pick the walnut like bits off.

[mumofstig]

It looks like it may be Crown Gall https://www.rhs.org.uk/advice/profile?PID=141.

If you decide to cut the odd bits off, to save it for next year, be sure to sterilise your knife and the cut tuber with some flowers of sulphur, to hopefully kill any lingering nasties.

[Ethel]

Thank you - think I'll just burn it to be on the safe side. And move my dahlias to a different site next year. This forum is so useful!