#7 Postcard Trivia 12.19.17

Four leaf clover Christmas Greetings, 1912. From the collection of J Garner.

Christmas Luck? This Christmas postcard was sent from Fort Morgan, Colorado, on December 18, 1912. I have a few vintage holiday postcards that are decorated with Christmas symbols - holly, snow, gifts, Santa, etc. I was not expecting, however, to find one with four leaf clovers. Surprisingly, when I searched images of postcards from this time period, I found many Christmas greetings cards with four leaf clovers and spring flowers. I looked up information about lucky four leaf clovers, but I could not find an explanation of why they would be associated with Christmas. This week's trivia question is:

Why are there four leaf clovers on a Christmas postcard?

Sorry, I don't have the answer! Please help me out if you can. I would love to know more about this trend from the early 1900's.