Planting trees to mark the passing of events and people is a longstanding tradition around the world. To better understand the contemporary practices of memorialization through planting, we examine living memorials created in response to the events of September 11, 2001. As an extension of the U.S. Forest Service Living Memorials Project, we reviewed existing data (n = 787 sites) and identified 223 sites where stewards mentioned planting 102 kinds of flora. Oaks (Quercus spp.) were most commonly mentioned (17% of sites), while 75% of plants/trees were named at only 1% or fewer sites, underscoring their diversity. We also visited 21 sites to document their flora and conduct interviews with stewards (n  =  34 stewards from 33 sites; 13 interviews were conducted by phone). We find that the symbolism of flora plays a role in continuing to keep memories alive at living memorial sites through flora traditionally used in death and memorial contexts; through more localized symbols particular to the sites as conveyed through the meanings of color, habit, and number; and through a newer symbol we identify, the callery pear (Pyrus calleryana) survivor tree. We also find that the community-based planting practices in public space are meaningful themselves, as they can serve as a mechanism to promote healing and recovery for communities and sometimes also promote the co-recovery of social-ecological systems.