Friends of John Broderick Hehman, the New York University student who died after being hit by a car on E. 125th St. on April 1 while fleeing four teenagers who were trying to rob him, will plant a tree in his memory on May 14. In addition to the tree planting in Maggie’s Garden, a community garden on W. 149 St. between Broadway and Amsterdam Ave., Hehman’s fellow students are raising a scholarship fund in his memory. The four suspects, ages 13 and 15, have been charged with felony murder.