Semi-public spaces in parking strips and alongside driveways and alleys could host thriving gardens that add beauty and provide ecological services.  Author Evelyn Hadden addresses issues such as car, foot, and paw traffic, utility and maintenance equipment, restricted root zones, contaminated soil, covenants and city regulations, and presents ideas for the greening of your neighborhood, on Wednesday, May 21, from 6:30 – 8:30 at Arnold Arboretum’s Hunnewell Building, 125 Arborway, Boston.  Co-sponsored with the Friends of Wellesley College Botanic Gardens.  Member of sponsoring organizations will pay $15, non-members $25.  Register at 781-283-3094, or email wcbgfriends@wellesley.edu.