Kitchen Garden Forum

Currently I'm growing bush beans indoors at the window because it's way too cold outside. With limited space I got no greenhouse and I was sort of experimenting around. Today I noticed one of my bush bean plants leaves getting yellowish spots between its veins and eventually weirdly curling up to the inside. It's only one plant, the rest of them look perfectly healthy! Anyone knows what this could be? I have checked for insects but nothing to be found...

Yellowing leaves between veins


Leaves curling up to the inside

I'd be looking for wee bugs usually with curled leaves, but they are perfect. The clever guys who will know will be along with the answer. They are so clever, giving hints & tips & answering questions, they have saved me from many a plant disaster over the years.