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. To become a certified Tree Tender, participants must attend 3 sessions for 9-hours of training, covering tree biology, identification, planting, proper care, and working within your community. Available for ISA, PA LA,PLNA, PA Master Gardeners and PA Master Naturalists credit. This course is intended for adults due to the late evening hours.