peat moss

American  

noun

1. Also called bog moss.  any moss, especially of the genus Sphagnum, from which peat may form.

2. such moss after it has been dried, used chiefly as a mulch or seedbed, for acidification.

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peat moss British  

noun

1. Also called: bog moss.  any of various mosses, esp sphagnum, that grow in wet places in dense masses and decay to form peat See also sphagnum

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peat moss Scientific  

1. Any of various mosses of the genus Sphagnum, growing in very wet places, especially bogs, around the world. The leaves of peat moss have large dead cells surrounded by smaller living ones that contain chloroplasts. The walls of the dead cells are perforated and readily absorb water, up to 20 times their dry weight. The walls also contain phenol compounds that resist decay and have antiseptic properties. Peat moss releases hydrogen ions that increase the acidity of the water in bogs. Because of its ability to absorb liquids, peat moss is sometimes used as diaper material by traditional peoples and was once used in making bandages. Peat moss is now used primarily to increase the water-holding capacity of soil.

2. Also called sphagnum

3. See more at bog

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Etymology

Origin of peat moss

1225–75 for earlier sense; 1870–80 peat moss for def. 1; Middle English petemos (in placename) peat bog

Example Sentences

Coconut fibers broken down by millipedes may serve as a sustainable replacement for peat moss, a material commonly used to start seedlings but often sourced from fragile wetland ecosystems.

From Science Daily • Oct. 12, 2025

To form the surface of a running track they were mixed with clay, peat moss, or ashes from burning coal, which held the surface together.

From BBC • Jul. 22, 2024

To grow one yourself, plant it in a well-draining potting mix with a pH range between 6.0 and 6.5, such as one amended with peat moss.

From Washington Times • Oct. 17, 2023

Seeds grow in six peat moss sponges encased in plastic pods — reaching their roots into the water at the unit’s base.

From Seattle Times • Jan. 27, 2023

In his eyes, the peat moss prank put my future in jeopardy.

From "Linked" by Gordon Korman

Related Words

• clay
• coast
• dirt
• dust
• gravel
• land
• mud
• sand
• shore
• surface
• terrain
• turf