Leek rust (/Puccinia porri, or Puccinia allii/) is uncommon, but a severe attack will ruin the crop. Mild symptoms do not render the crop inedible. Leek rust is different from the rust that infects chives and onions.
Appearance of leek rust:
* orange spots & blotches appear on the surface of the leaf
Causes of leek rust:
* crowded plants * high humidity * excessive soil nitrogen * insufficient soil potassium * poor garden hygiene - all plant debris must be removed from the beds so that the fungus has nowhere to hide.
Treatment of leek rust
* remove and burn diseased leaves * there is no chemical treatment available to use in the kitchen garden
Prevention of leek rust * do not plant the leeks too close * rotate crops - do not grow leeks where leeks & onions were grown the previous year * apply a potassium rich fertiliser (such as tomato feed) * grow disease resistant varieties * practise good garden hygiene, and keep the vegetable garden tidy