City of College Park, Maryland

Public Works

How SMARTLEAF® Compost and Wood Mulch are Made

SMARTLEAF® Compost & Wood Mulch
Prices, Pickup, and Delivery Options
Compost vs. Wood Mulch: Which One and How Much do I Need?

College Park's Composting Process

susie smartleaf

Suzie SMARTLEAF® says:

It is important to keep your vegetative yard waste (grass, leaves, flowers, weeds, and light clippings), separate from wood yard waste (branches, twigs, sticks, shrubs, bamboo, logs) because they are recycled in different ways. Vegetative yard waste is used to make SMARTLEAF® compost while wood-based materials are made into wood mulch.


Public Works crews collect vegetative yard waste (leaves, grass clippings, flowers, and light clippings) in paper bags or reusable containers, or with the leaf vacuums.

This material is brought to the Public Works compost yard and spread out in long windrows.

paper yard waste bags

leaf vacuum

compost windrows



A windrow turner passes over the rows, mixing the material and introducing more oxygen to help the natural decomposition process.

As microbes start to break down the material, the piles reach temperatures up to 140° F which kills any pathogens and weed seeds that may be present.




After several months of decomposition, heating up, and turning, the vegetative materials no longer have harmful levels of carbon dioxide or ammonia and the result is a fully matured compost product.

Mature compost is screened to remove debris and large particles over 5/8 inch in size. The compost is now ready to be mixed in with your existing garden soil as an amendment or as a top dressing for your lawn.


SMARTLEAF® compost

DISCLAIMER: Since all of our products are municipally collected there is the potential for foreign material in them. Our products are not chemically treated.

What does not belong?

Here is an example of the types of items that are screened out of the compost. Bottles, cans, dog toys, etc., DO NOT belong in your yard waste! We appreciate your efforts to remove these items to help us maintain a high quality compost product.

trash in compost




How is Wood Mulch Made?

Simple – we collect twigs, sticks, branches, small trees, shrubs, bamboo, and logs (stacked neatly or tied with string, less than 5 feet and 75 pounds) curbside and bring it back to the Public Works department.

Once we have a large pile, a tub grinder processes the material to make the mulch. A series of hammers grinds up the wood and a conveyor belt moves the final wood mulch product into a pile. The mulch is not screened, so it is important that residents keep out plastic bags and debris.

tub grinder

wood mulch

DISCLAIMER: Since all of our products are municipally collected there is the potential for foreign material in them, such as pieces of plastic, sticks, wire or glass. Our products are not chemically treated.