mulch
noun
[ mʌl(t)ʃ ]
• material (such as decaying leaves, bark, or compost) spread around or over a plant to enrich or insulate the soil.
mulch
verb
• treat or cover with mulch.
• "the perennials have been cut back and mulched"
Origin:
mid 17th century: probably from dialect mulch ‘soft’ used as a noun, from Old English melsc, mylsc .