This weekend is shaping up to be downright spring-like, perfect for this cool and unusual event I heard about from my friend Melissa. The Boston Tree Party is on a mission to plant 100 pairs of heirloom apple trees in public spaces across Greater Boston and the inauguration party kicks off this Sunday at 1pm at the Rose Kennedy Greenway. (Apparently, once the trees bear fruit, anyone is welcome to pluck a healthy snack -- awesome!) Featuring the ceremonial planting of the first pair of heirloom apple trees, music, refreshments, and other civic-minded activities, this event offers a cool way to teach kids about community, urban agriculture, and the all important lesson of sharing. And of course before or after the inauguration, there's no shortage of family fun to be had in the area, whether you hit, say, the Aquarium, Christopher Columbus Park, or walk a little further for gelato in the North End.