Humus

Humus refers to all the dead organic matter in the soil that has already been broken down by soil organisms. It is dark in colour, crumbly, and considered the heart of fertile garden soil. Humus stores nutrients, improves soil structure and promotes soil life.

How does humus form?

Humus forms through the decomposition of plant remains, roots, leaves or garden compost. Earthworms, microorganisms, fungi and bacteria break down the organic material step by step. At the end of this process, a stable, nutrient-rich substance remains that stays effective in the soil over the long term.

Why is humus so important?

• Improves soil structure and creates a loose, crumbly texture
• Stores water and nutrients
• Promotes active soil life
• Increases soil fertility

Sandy soils in particular benefit from humus, as it helps them retain water and nutrients better. Heavy, clay-rich soils become looser and better aerated through humus.

Building up humus in the garden

A healthy humus content can be encouraged through regular applications of garden compost, mulching, growing green manure or working plant remains into the soil. A diverse range of planting also supports soil life and, with it, humus formation.

Humus is not the same as fertiliser

Humus supplies nutrients, but its main effect is long-term structural improvement. It does not replace targeted fertilising for heavy feeders, but it forms the basis for sustainable soil fertility.

Conclusion for home gardeners

Soil rich in humus is alive, stores water and reliably supplies plants with nutrients. Anyone who cares for their soil and returns organic matter to it creates the best basis for healthy growth and good yields.