The plant palette collectively devised by the designers, Gateway Foundation, and the horticulturalists at the Missouri Botanic Garden emphasizes native Missouri trees, shrubs, grasses, groundcovers, and wildflowers. Plant selections were made and planting designs were developed to ensure the long-term success of the plants, and emphasize the four distinct seasons. Plant species and cultivars were chosen for their urban and drought tolerance, and most plant choices and their specific locations were determined by their relative hardiness and particular tolerances for varying degrees of sun, shade, wetness and/or dryness. In addition, the opportunity to use this project for teaching purposes was fundamental to the planting and soil strategy, in both design and technical detail. This will be an urban botanical garden of sorts, with plants and garden areas labeled, and with every intention of using the design to demonstrate sustainable garden practices in urban settings.
The garden is also home to 1,400 square feet of sedum-dominated green roof. More than 5,000 square feet spread over six rain gardens will collect and infiltrate stormwater from two-thirds of the site's surfaces. Despite extensive paved areas for pedestrian activity, nearly half the site is designed to be permeable. Three different soil mixes were devised to replace the rubble-filled and over-compacted existing site soils and provide a healthy substrate in which the various plant communities could thrive.
Trees planted within pavement zones are given generous room for trunk and root growth. Most significantly, several strategies were employed to minimize compaction issues with these urban trees. These include the use of a slab-and-pier construction system that permits unimpeded root growth in many of the terrace and street areas. In places where this system could not be used, structural soils were utilized.
In total, the garden includes 235 trees, comprised of twenty different species. Of the 89 other species of plants, there are 1,170 shrubs, 4,194 perennials, native grasses and wildflowers, 8,000 bulbs, 12,726 groundcovers, and 32,000 square feet of lawn.
To learn more about the flora of Citygarden, download The Plantings from the online press kit.