Tu BiShvat (Hebrew for the 15th day of the Hebrew month of Shvat) is the new year of the trees.
Rabbi Julie Zupan answers - When do you light yizkor (memorial) candles on Yom Kippur? Do you light candles only for immediate family members?
Jewish communities around the world marked the "new year for the trees" last week with tree planting ceremonies and seders that celebrate Israel's seven species (wheat, barley, grapes, figs, pomegranates, olives and dates if you are keeping track!).