Humus is the dark, nutrient-rich layer of decomposed organic matter that forms in soil. When leaves, dead plants, fallen branches, and other natural materials break down over time, they transform into this crumbly, almost black substance that looks and feels a bit like very fine coffee grounds. Humus makes soil fertile and healthy, giving plants the nutrients they need to grow strong.

The process takes months or years. Bacteria, fungi, worms, and countless tiny organisms work together to break down the organic material into humus. Gardeners and farmers value humus because it helps soil hold water and air, creating a great environment for roots. If you've ever noticed how dark and rich the soil is in a forest compared to sandy beach soil, you're seeing the difference humus makes.

Don't confuse humus with hummus, the delicious Middle Eastern dip made from chickpeas. They sound identical but mean completely different things.