I had never heard this before, and I can't find any confirmation of the claim, but I hope it's true! There's not much left of Ebbets Field — its former site is occupied by high-rise apartments.
Something else I learned from this informative wall: "Before its original 39 acres were designated for a botanic garden in 1897, the Garden's land was covered in trash, construction rubble, and ashes from its history as a city dump."