material, for example, decaying leaves, that you put around a plant to protect its base and its roots, to improve the quality of the soil or to stop weeds growing 覆盖物，覆盖料（用以保护植物根基、改善土质或防止杂草生长） Oxford Collocations DictionaryMulch is used after these nouns:- bark
Word Originmid 17th cent.: probably from dialect mulch ‘soft’ used as a noun, from Old English melsc, mylsc.