Fallen tree branches are collected and accumulated from all New York City parks from now until May 2013, and are stockpiled at Socrates Sculpture park. Formwork is constructed out of plywood for the inner shells of the walls. A rebar structure is erected with a dual function - to provide reinforcing for the concrete, but also as structural support for the cantilevered branches. The bottom row of branches are installed, with the cut ends of the branches flush against the plywood. The formwork for the outer shell is formed out of a mixture of sand, dirt and hay. Each row of branches is subsequently installed, with the earthen formwork deepening as required. Some of the lower branches will be completely engulfed by the temporary earthen formwork.
Concrete with recycled glass aggregate is poured between the plywood and earthen formwork. The earthen formwork is power-washed away using water from the adjacent East River, leaving the concrete between the exterior branches dirty and imperfect. The plywood formwork is removed and the inner shells are ground down and subsequently polished, creating a perfectly smooth surface of exposed ends of branches, concrete, and the shimmering glass aggregate.