Have you made your wish yet? Yoko Ono’s Wish Tree for Washington, DC art installation is back on the mall this summer. Making a wish is simple: head to the Smithsonian Hirshhorn Museum and Sculpture Garden before Labour Day and find a dogwood tree across from Giacometti’s “Monumental Head.” Make a wish. Write it down on a piece of paper (pencil and white paper tags are provided). Fold it and tie it around a branch of the Wish Tree. I made my wish earlier this summer, though I’m still waiting for it to come true. Like the love locks in Paris, which are frequently removed by the city, museum staff will clear up the tree several times a week throughout the summer so that there is room for ...