Thatch (lawn)

Thatch is a combination of living and dead plant matter including crowns, stolons, rhizomes, and roots.

Grass clippings do not generally contribute to thatch buildup as they can be easily broken down by soil microorganisms.

Thatch is composed of about 25% lignin, a complex organic polymer that is highly resistant to decomposition.

Thatch buildup can be caused by several factors: A small amount of thatch may provide a beneficial insulating effect against fluctuations in temperature and moisture.

However, excessive thatch can cause root problems and lawn mower difficulties.