Historical urban parks are particularly valuable in terms of their ecology, as they offer habitats to many valuable flora and fauna. A study was conducted in Felin Manor Park, Lublin, southeastern Poland, dating back to the end of the nineteenth and the first half of twentieth century. The aim of the study was to assess the suitability of this type of urban park for the proecological design of urban green areas that will comply with the legal requirements for historic gardens. The investigation demonstrate that long-living native tree species (e.g., Tilia cordata, Quercus robur, and Fraxinus excelsior) are the best preserved plants in this park. The dendroflora of the park is, however, characterized by a great variety of species flowering between early spring and fall. These reward species ensure continuity of the food base for insects throughout the vegetation season. A floristic inventory facilitated development of a concept for the restoration of the park combining cultural (historical, educational) and ecological functions. Tilia cordata was used for line planting arrangements along the park boundary. It is a component of the alley design along the driveway and is one of the most valuable nectar reward species. The survey allowed the definition of future design guidelines, i.e., the preservation of the historical park structures (formed by long-living native species) and complementation of the park dendroflora with species that are attractive for bees and other insect pollinators. To supplement their food base, it is recommended that a “bee garden” with herbaceous reward plants should be created.