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Hello all, complete novice here.... can anyone tell me why, after pulling rhubarb, the newly grown leaves are going all rusty coloured?, not completely but a lot of the new leaves....What am i not doing right/should be doing? any help appreciated.......

I believe it is purely down to this time of year, with the heat etc.
Nothing to worry about.

The plants should recover with cooler weather and rain.

Yeah - rubbard starts to die back at this time of year, dont worry about it.