By Molly Daly

PHILADELPHIA (CBS) — The Streets Department launches its Philly Leaf and Recycling Program today. In the fall, trees get ready for winter by cutting off the flow of nutrients, essentially giving leaves the heave-ho. It’s illegal to burn them in the city and since composting turns them into garden gold, putting leaves in the trash seems downright wasteful.

Conservation-minded Philadelphians can drop off leaves in biodegradable bags at 23 locations, Saturdays from 9-3 through late December, as well as at the five Sanitation Convenience Centers. They’ll also be doing mechanical leaf collection.

Deputy Streets Commissioner Donald Carlton says they’ll be put to good use.

“They will be used as mulch, and as a bulking agent for the composting process,” Carlton said.

If you have the space, you can compost them yourself. Morris Arboretum Executive Director Paul Meyer says the resulting humus is full of nutrients, and that’s not all.

“It helps to build the soil structure, to make the soil looser, easier to work, and it also helps provide more oxygen, for the roots of plants growing in the soil,” Meyer explained.

Or you can let fallen leaves lie on your lawn.

“I mow one more time and grind them. If it’s not too heavy, you can leave them right there, and they’ll compost in place.”

From April through October, the finished product is available at the Fairmount Park Organic Recycling Center on Ford Road. For city residents, there’s no charge for small amounts of compost, mulch or manure. There’s a fee for anything more than what’ll fit in a 30 gallon container.