The primary goal of this project was to reinstate the continuous formal tree rows-- the single most important landscape feature of the original design. The parkway's edge (as defined by its surrounding architecture), alignment and focal points (e.g. Art Museum, sculpture, fountains) were all unchanged, as were the relationships between its streets, sidewalks, curbs and medians and as such were being preserved. Next came the determination of treatment. For this replacement decision, preservation was not an option since most of the trees were already lost. This left rehabilitation and restoration treatment options. Reconstruction was not considered a treatment alternative since the majority of the spatial qualities, features and materials that comprise the parkway survive today. Research, existing conditions and assessment substantiated a decision to remove the remaining red oak trees and replace the entire four rows of trees along the two medians. The replacement of the parkway trees in their original locations with the original red oak monoculture (a restoration approach) was rejected as an ecologically unsound and unsustainable alternative. New parkway tree plantings. Projected growth two years after construction. (courtesy South Street Design) New parkway tree plantings. Projected growth fifty years after construction. (courtesy South Street Design) Soil preparation, improved drainage and a mixture of disease resistant trees were all seen as essential to the success of a replanting effort. In order to incorporate all of the relevant factors and reinstate the tree plantings without strict adherence to a plant monoculture in the historic design, a rehabilitation treatment was chosen. Rehabilitation permits replacement of an extensively deteriorated historic feature with compatible substitute material, if such material conveys the appearence of the historic feature. The rehabilitation treatment addressed all of these issues. It would retain the Beaux Arts formality of the parkway while incorporating contemporary knowledge and techniques of urban ecosystems and tree health. Hence, replacing the allees using urban-tolerant trees in mixed species planting rather than a monoculture, was selected. These new allees were to be planted in a manner that would sustain their health and contribute to their longevity. Three species were chosen with similar form, scale, color and texture. The goal of the tree selection was to have the chosen trees grow at approximately the same rate, reach an equivalent mature height, provide a similar leaf size and branching pattern, and, therefore, blend into a continuous row.