A 4,5-dichloro-imidazole-1-carboxylic acid aryl ester of the formula ##STR1## in which X represents a group ##STR2## in which R.sup.2 and R.sup.3 conjointly with the adjoining nitrogen atom form a morpholine, thiamorpholine, or piperazine ring,Y represents halogen, alkyl with 1 to 6 carbon atoms, trifluoromethyl, alkoxy with 1 to 6 carbon atoms, alkylmercapto with 1 to 6 carbon atoms, nitro, cyano or ##STR3## in which R.sup.4 represents alkyl with 1 to 6 carbon atoms and n represents 0, 1, 2, 3, 4 or 5,which possesses plant protection properties especially herbicidal and plant growth regulant properties.