Tree pits along 14th St. were, well, the pits — until the Union Square Partnership recently “remediated” 56 of them in its business improvement district at a total cost of $71,000. The old, metal tree pit grates from 1991 (at left) were unsightly and hard to maintain. Trash collected in them; weeds grew through them. Tree truck guards were eventually removed from around some of them, but the tree roots began to shift the grates, creating trip hazards. The recent renovation removed the grates. An arborist then aerated the soil, which had compacted under the grates. Next, a liquid fertilizer was infused into the pits. The soil was then topped with 4-square-inch granite cobblestones (above), with crushed bluestone in between, a treatment allowing flexibility for tree-root growth. Finally, mulch was added. The renovated pits are between First and Third Aves. and Fifth and Sixth Aves. on both sides of the street, and on 14th St.’s south side between University Place and Fifth Ave.
