Hi Charles
I h ve had the same problem on my cucumbers and thought it might be magnesium so I dowsed with Epsom salts twice and it did not work, so a mentor said he thought it was red spider mites and when I looked real close at the leaves I did see tiny webs so I have spent money on the predators and hope that works so they don’t over winter! it is a shame as I have lost 2 cucumber plants and the melon looks unwell. I spoke to Mike at Defenders of wyebugs he was really helpful. I hope you can sort it out. Ali
