sunflowers problems

[stevie77]

we have set some 'evening sun' and 'giant' sunflowers which are all over a foot high now BUT they are getting a funny colour on the leaves.
it looks as if they have been dipped in a deep red/purple/brown dye.
any ideas please?
steve

[stevie77]

[valmarg]

The only suggestion I can make is rust. ???

valmarg

[manicscousers]

some of ours went like that last year, plus some looked as if they had been splashed with different colours, they still gave us some lovely flowers , provided the growing tip looks okay, the flowers should be too  :)