New York City's mandatory composting program is now up and running in all five boroughs.

That means that city residents must separate their organic refuse from their household trash and place it at the curb in a separate bin for collection.

But some residents have wondered: do they have to place their leaves, grass clippings and other yard waste in their compost bin for collection?

Many Staten Islanders and others are used to putting their yard waste at the curb in brown paper bags or clear plastic bags.

They can continue to do so, according to the city Sanitation Department.

"While food waste must be placed in sealed bins to keep rodents, raccoons and other animals from breaking in and making a mess, leaves, twigs, grass clippings and other yard waste can be left at the curb in brown paper bags or clear plastic bags," said department press secretary Vincent Gragnani.

If they want to do so, however, city residents can place their yard waste in their official brown composting bin, according to the Sanitation website.

City residents can also place their yard waste in a yard waste-only bin. The bin should have an official "Yard Waste Only" decal on it.

Bundles branches can be set out in bound bundles measuring 2 feet by 4 feet or smaller, the website says.

Organic material that needs to be composted also includes food waste like meat, bones, dairy, fruits and vegetables.

Food-soiled paper products like napkins, tea bags and paper plates will also need to be separated.

Compost can be placed in a clear plastic bag and placed in the compost bin for disposal. Ordinary white kitchen trash bags and black bags cannot be used.

Non-soiled paper products should remain with traditionally recycled materials.

Items like wrappers, medical waste, diapers, foam and hygiene products should remain in the traditional trash.

Pizza boxes can still be recycled as long as they are free of cheese residue.

Pet waste such as kitty litter should continue to be placed in the normal household trash.

You can purchase an official New York City composting bin here.

You don't need to have an official compost bin. You can dispose of compost in any bin 55 gallons or less with a secure lid.

The bin should be labeled with an official compost bin decal, which you can get for free here.

Compost should be placed at the curb for pickup on the same day that recyclables are put out.