The City of Modesto first implemented its integrated composting program in 1997. The program includes collecting and processing residential yard waste material from the green cans and pruned refuse from the street collection program. Over 50,000 tons per year of organic material is recycled. The material is combined together to make Modesto's own Mo-Gro-Pro, a clean green compost. The compost is sold back to the community in 1 cubic foot bags or in bulk quantities.

Compost is an organic soil conditioner created by decomposing organic matter under controlled conditions. Compost improves water-holding capacity, soil structure, porosity and density creating a better plant root environment. Compost supplies a variety of macro and micro-nutrients including nitrogen, phosphorus, potassium, calcium, magnesium and more!

Composting is the process of rapidly decomposing organic matter using aerobic (oxygen-using) microorganisms at high temperatures followed by a more gradual decomposition of any remaining by-products at more moderate temperatures.

Our Process 

The compost facility receives approximately 200 tons of community yard waste (grass, leaves, brush and tree trimmings) each day. Yard waste is high in nitrogen and is mixed with chipped branches to add carbon content. After grinding, the chips are placed into rows (windrows) and further processed by watering and turning. The internal row temperatures range from 132 to 150 degrees which kills weed seeds and bacteria. After about three to five months, the result is a humus-like product ready for use.

Testing & Assurance Program 

The City of Modesto's compost is laboratory tested and qualified for sale per the standards set by CalRecycle and the U.S. Composting Council. Modesto's Clean Green Compost is also listed by the Organic Materials Review Institute (OMRI) for use in production of food and fiber.