Help plant and care for trees in your region, your community, or your yard. Become a PHS Tree Tender! The PHS Tree Tenders® program offers hands-on tree care training for residents of the five-county Philadelphia region. The training covers tree biology, identification, planting, proper care, and working within your community. Available for ISA credit. This course is intended for adults. The class will be held on three consecutive Wednesdays Sept. 18, 25 and Oct. 2 from 5:45-9:00 PM.