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. This 9-hour, single-day intensive Tree Tenders class will be held at the Greater Plymouth Community Center with indoor and outdoor sessions. Available for ISA credit.