Potbelly Sandwich Shop's cherry blossom shake is back for the spring. This year, the District's shops are donating 20 cents from every purchase of the pink treat sold through May 1 to go toward tree planting at 22 local schools. The trees are being provided by Casey Trees, a D.C.-based nonprofit committed to restoring the city's tree canopy. Potbelly's around the Washington region will also donate 20 cents from each milkshake sold to the Arbor Day Foundation, a nonprofit dedicated to planting trees throughout the nation. -- Courtney Zott