Morgan Hill, CA — October 23, 2025 — Monterey Mushrooms, the premier vertically integrated mushroom grower in the United States, is proud to announce the certification of its Organic Spent Mushroom Compost (COSMC) by the California Department of Food and Agriculture (CDFA). The rigorous 24 month certification process recognizes Monterey Mushrooms’ passion and deep-rooted commitment to sustainability and responsible stewardship of natural resources. It recognizes the care and innovation woven into every part of its operations, from the way the mushrooms are grown to how the byproducts are managed. By giving new life to the spent compost in a certified organic form, Monterey Mushrooms is closing the loop on its growing process and creating additional value for farmers, gardeners, and the environment alike.

"Earning CDFA organic certification for our spent compost was no small feat! It was the result of nearly two years of rigorous work and dedication across our teams. The process required detailed documentation, strict compliance with regulatory standards, and ongoing audits to ensure every step met the highest organic requirements,” shared Chris Thomsen, Operations Manager for Monterey Mushrooms. “We’re proud of this achievement because it demonstrates not only our commitment to sustainability, but also the care and discipline we put into producing a product that supports organic farming and environmental stewardship."

Mushrooms are already one of the most sustainable foods on the planet, requiring minimal water, land, and energy to produce. Building on that advantage, Monterey Mushrooms strives to make every aspect of its business—from farming and packaging to transportation and product development—more environmentally responsible. This organic certification is not only a reflection of the company’s efforts but also a step forward in its ongoing mission to leave a lighter footprint and contribute to a healthier planet.

Keith Day, Owner of Keith Day Gabilan Ag Services shared, “We’ve been helping Salinas Valley farmers care for their soil since 2002. And, no matter if it’s orchards or vineyards  or maintaining landscapes, we see consistent quality and sustainable results for every grower when we incorporate certified organic spent mushroom compost from Monterey Mushrooms into our custom compost blends. The outcomes show that it naturally improves soil health, boosts moisture retention, and supports strong plant growth.”

Row crop and leafy green farmers throughout the Salinas Valley now have access to a reliable, high-yield alternative to synthetic fertilizers. A finely balanced mixture of straw, peat moss, cottonseed meal, mined gypsum, mined lime, and other natural ingredients, COSMC is a nutrient-rich, natural soil amendment designed to enhance soil fertility, optimize productivity and achieve healthier, higher-quality harvests across a wide range of crops and landscapes.
Key Benefits Include:
Improves Soil Composition: Loosens heavy soils and enhances aeration while helping sandy soils retain moisture.

Boosts Fertility Naturally: Provides humus, organic matter, and light fertilization to support vigorous plant growth.

Enhances Water Efficiency: Increases water-holding capacity, reducing the need for frequent irrigation.
pH Balancing: With a natural pH in the range of around 8.0–8.3, Mushroom Compost can help neutralize acidic soils and serve as a sustainable alternative to lime.
Versatile Use: Ideal for amending planting beds, vegetable gardens, topdressing lawns, and as a sustainable alternative to synthetic fertilizers.
Certified Organic Spent Mushroom Compost is available wholesale to businesses by the cubic yard. Visit www.montereymushrooms.com/wholesale-organic-spent-mushroom-compost for more information or to inquire about an order.

About Monterey Mushrooms
Founded in 1971, Monterey Mushrooms® is passionate about enhancing people's lives with fresh, locally-grown mushrooms sourced from four strategically-located farms in North America. Dedicated teams harvest vitamin-d rich mushrooms daily to ensure the delivery of the freshest, whole and sliced varieties, to favorite grocery stores and restaurants around the world. Monterey Mushrooms is proud of its 55-year legacy and unwavering commitment to innovation, sustainability, and food safety. Learn more about Monterey Mushrooms’ offerings at www.montereymushrooms.com and through their social channels: Facebook, Instagram, and explore career opportunities at LinkedIn.