I have just done some research to work out why people in Wales wear a leek or daffodil on this day. Well leeks represent the fact St David (Dewi in Welsh) was a vegetarian and one of the meals he ate was leek cawl (a leek soup). Leeks are supposed to be good for health.Daffodils came later when they were worn at the investiture of the Prince of Wales at Caernarfon.
I can remember wearing a leek to school and I liked raw leeks by the time it came for my leek to be judged there was nothing left I had eaten it all.
Perhaps I ought to eat more leeks and see if my health improves.
Best wishes to everyone celebrating St David's day.