The Hirshhorn Museum and Sculpture Garden in Washington, D.C., is about to reopen its sculpture garden after a $68 million redesign by the artist and architect Hiroshi Sugimoto.

The new garden, which opens to the public on 31 October, reorganises the 1.3-acre space across Jefferson Drive from the museum building itself. Some 30,000 new plants and trees have been added, reshaping a garden that had changed little since it first opened.

Access has been substantially expanded, with five entrances and new overlooks at the east and west ends of the site. The redesign also restores features of Gordon Bunshaft's original architecture for the garden that had long been closed to visitors.

Auguste Rodin's The Burghers of Calais is among the works installed in the reworked landscape, set against stacked stone walls that form part of Sugimoto's design. The garden's collection of modern sculpture will now be encountered along new paths and sightlines.

The reopening marks the end of a long and closely watched project for the Smithsonian museum, whose garden is one of the few free outdoor sculpture spaces in the American capital. Its return gives Washington a redesigned public landscape at a moment when the museum is also rethinking how its collection meets the street.

The garden sits on the National Mall, between the museum's drum-shaped building and the Mall's open lawns, and entry is free. Its reopening restores one of the few places in central Washington where modern sculpture can be seen outdoors without a ticket, and where the museum's collection meets the city at street level.