The other simanim eaten on Rosh Hashana contain a play on words with the name of the food and either a wish for a good omen or a wish for bad to befall our enemies. The yehi ratzon for the apple has ...
Where did the idea of doing a Seder on Tu b'Shvat come from? Why a Seder, not just the eating of fruit? Why do we call it a Seder if there is no formalized way of doing it?