Success! Tactfully told him that I could find NO information on the use of caustic soda to enhance onions and that potash sulphate was the normal thing used. He thought for a bit and said "The spiteful old sod! Uncle Bill must have been making sure I couldn't grow onions as big and nice as his....

Thanks, I will try that. He usually listens when I tell him I have done research on the internet.

My 83year old father is insisting I sprinkle caustic soda around the onions on my allotment! He is obviously wrong, but he says his uncle used to grow giant onions that were very strong tasting, and he did this. Does anyone have an idea what my father is getting confused with? I am running out of ex...