A container garden on a grand scale is at Mellon Square Park in Pittsburgh, Pennsylvania. Viewed from above, this almost one and a half acre park presents a magnificent spectacle with its attractive design, well planted beds, and patterned pavements. Mellon Square Park, built in 1955, covers a six-floor underground parking garage for 1000 cars. An eighteen-inch roof holds up containers made of reinforced concrete, capped and faced
with polished Minnesota gray granite. Drainage lines and irrigation pipes for the planters were installed during construction.
The minimum depth of the planters is fourteen inches; here English ivy and trailing euonymus are grown. Other planters, ranging in depth from twenty-four inches to four feet, hold large deciduous trees. Watering is by means of installed bubblers and sprinkler heads, supplemented by considerable hand watering with short sections of hose. Plants are fed a dry complete fertilizer in early spring, followed by applications of liquid fertilizer in late spring and midsummer.
Planting material was selected on the basis of appropriateness for the design and its ability to withstand soot and grime, fumes from automobiles, and wind that sweeps between tall buildings. There are three enormous neatly-sheared Japanese yews, and the trees include European beech, honey-locust, sourwood, little-leaf linden, sweet-gum, sophora, sweet bay magnolia, and crab-apples.
Hahn's Shamrock, are used as ground covers. In spring, there is color from bulbs; these are followed by annuals and chrysanthemums for summer and autumn displays. Some tropical plants, crotons, pandanus, acalyphas, shrimp plant, and hibiscus, are in a special box, which is also used for a Christmas tree display. For protection against winter injury, plants are sprayed with Wilt-Pruf in early November when the weather is bright, warm, and sunny.
Beautifully maintained, Mellon Square Park is considered "one of the most outstanding examples of redevelopment in an urban area. Surrounded on all four sides by skyscrapers, the park is a cool and inviting oasis to the tired shopper, the harried executive, and the multitude of workers who are employed in the downtown area."
In the midst of concrete and steel, where gardening in the open ground is not possible, Mellon Square Park represents a large-scale garden created in boxes and planters-an outstanding and successful example of this new gardening concept.