"Donna (UK)" writes
Afternoon all

I brought a small rhubarb plant from Wilkos and it has produced two
stalks/leaves. One of the leaves started to yellow and the stem started to
go soft.

I would have thought that that particular leaf had simply reached the
end of its useful life.

Don't worry as long as the other leaf is healthy.

If the other leaf isn't healthy, then return it to the shop and ask for
a better replacement.
--
Kay