This might answer your question, Mama Bear:
David’s Day
Traditions
Children take part in school concerts or eisteddfodau, with recitation and singing being the main activities. Formerly, a half-day holiday was afforded to school children. Officially this custom does not continue, although the practice can vary on a school-to-school basis.
Many Welsh people wear one or both of the national emblems of Wales on their lapel to celebrate St. David: the daffodil (a generic Welsh symbol which is in season during March) or the leek (Saint David’s personal symbol) on this day. The association between leeks and daffodils is strengthened by the fact that they have similar names in Welsh, Cenhinen (leek) and Cenhinen Bedr (daffodil, literally “Peter’s leek”).
Males usually wear leeks while young girls wear daffodils. The younger girls usually wear their Welsh costumes to school. This costume consists of a long woollen skirt, white blouse, woollen shawl and a Welsh hat.
The Welsh flag is always flown in honour of St. David on days in which he is honoured or commemorated.
http://en.wikipedia.org/wiki/Saint_David‘s_Day
Leeks! St. David’s personal symbol. So, that’s what they are! Thanks, yorkie. I am getting quite an education today. I love learning new things!