Sunflower is sign of luck in Germany, at least as my late Professor Dr Karl-Hermann Neumann told me on visit to his home in Hungen near Giessen in state of Hessen of Germany. He was leading a peaceful life in woods of Hungen after retirement . He invited me to his place and took me to a restaurant.
It was written on the wall opposite a bench " Die hier sitzen, immer hier sitzen " I am not able to give exact words but it meant " Those who sit hier always sit here" I visited the restaurant again this summer and felt that  he is still sitting there though he passed away in 2009. Atleast the memories of him are always there at that place.
In Hungen sunflower is considered sign of good luck . People make sunflower out of hay and sell it in the market for tourists.
Sunflower has great pesticidal properties. It also acts as insect repellent. It has high oil contents and people cultivate as renewable sources of energy.
Sun provides almost 97 percent of the energy needs of the earth and its inhabitants .
No doubt sunflower which symbolizes sun is sign of luck for many people .