Hugh Eaton wrote:

I planted 3 Rhubarb crowns at the end of October. Everybody else's around me
seems to be sprouting but mine is doing nothing. Out of curiosity i
carefully dug one up and it seems to be exactly the same as when I planted
it; it doesn't appear to have rooted and I'm worried that crown it's just
rotting. Any suggestions?

Leave it on the surface and let the frost get at it (rhubarb came
from Siberia originally). Plant in the Spring with a load of well
rotted manure. Don't harvest this year and perhaps next year either.
After that it should be fine.
--
Nick Wagg