Saint David was a monk who is said to have lived on bread, water, herbs and leeks, he founded a monastery with a very strict monastic brotherhood that had to work very hard besides praying and celebrating masses. They had to get up very early in the morning for prayers and afterwards work very hard to help maintain life at the monastery, cultivating the land and even pulling the plough. Many crafts were followed beekeeping, in particular, was very important. The monks had to keep themselves fed as well as the many pilgrims and travelers who needed lodgings. They also had to feed and clothe the poor and needy in their neighborhood.
 

March 1 was chosen in remembrance of the death of Saint David in 589 and was declared a national day of celebration within Wales in the 18th century, it is customary on that day to wear one or both
of the national emblems of Wales a daffodil and/or a leek.
 

Legend has it that the Welsh were battling the English in wet, muddy conditions. The Welsh leader (some say it was David himself), on seeing they were fighting in a field of leeks, told his troops to wear a leek in their hat to distinguish friend from foe.
The Welsh won the battle and the leek has become synonymous with Wales ever since. Since the Welsh word for leek is Cenhinen (leek, a large version of a green onion) and the word for daffodil is Cenhinen Bedr (daffodil, literally "Peter's leek"). The similarity between the two words has led to the daffodil being adopted as the Welsh national flower.
In some circles it is said that the daffodil was not used as a national symbol until it was promoted as such by the Welsh born Prime Minister, Lloyd George.