What is humus?

Humus is the dark-colored organic material that forms in soil when plant and animal matter decays… very different from the delicious snack called hummus made from chickpeas! 

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When plant and animal matter is collected in a composting environment with an ideal balance of oxygen, light, and bacteria, it will break down into humus. However, if plant and animal matter is collected in a landfill environment where the conditions aren’t ideal for decomposition, these materials will release methane, an extremely harmful and potent greenhouse gas.

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How is humus made?

Humus can occur naturally or be man made through a process called composting. Naturally-occurring humus is created when plants drop leaves, twigs, and other material (aka leaf litter) to the ground, and it piles up and decomposes over time. When plant matter (like leaf litter) and animal matter decomposes, it breaks down into its basic chemical elements, which often are very good nutrients for soil and plants. The dark brown or black substance that remains after the decomposition is completed is called humus. On the other hand, when people collect decaying organic material, like food and garden scraps, and store it in an environment optimal for decomposition (aka composting), that also can form humus.

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Is humus “good”?

Humus is great for soil. Not only does it provide plenty of important nutrients like nitrogen, but it also makes soil more fertile and helps prevent disease in some plants and food crops. When soil has humus in it, the soil will crumble, making it easier for air and water to move through the loose soil. This allows oxygen to more easily reach the roots of plants. 

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What kind of products are made with humus?

Humus is not an ingredient typically found in products, though you can buy it for your garden. 

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Are there certifications I should look out for?

No certifications here! Anybody can create humus in their backyard by composting.

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Still want to learn more? Check out some of our favorite references:

• Humus | National Geographic Society
• What Do ‘Compostable’ and ‘Biodegradable’ Actually Mean? - Finch

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