Every residential address in the five boroughs will have weekly curbside compost pickup by October 6, the Sanitation Department announced Wednesday, completing a rollout that began as a Brooklyn pilot and grew, in the words of one official, "one banana peel at a time."

Brooklyn already leads the city in participation. The borough diverted 4,100 tons of food scraps and yard waste in July, more than a quarter of the citywide total, with the highest set-out rates recorded in Park Slope, Bay Ridge, and, to the department's stated surprise, Canarsie.

"Canarsie decided composting was a competition, and honestly we encourage that," said Deputy Commissioner Ana Sepúlveda, who noted that the district's tonnage has tripled since a civic association began publishing block-by-block standings in a newsletter.

The expansion adds 340,000 addresses, mostly in Queens and Staten Island, and comes with an enforcement grace period through March, after which buildings that mix food waste into regular trash face fines starting at $50. Free brown bins are available through 311, though Sepúlveda urged patience on delivery times.

The department is also adding 200 smart compost drop-off bins, the orange ones unlocked by app, with 60 slated for Brooklyn locations including Grand Army Plaza and the Sunset Park greenmarket.