Novel substituted pyridyl-phenyl ethers of the formula ##STR1## in which X represents trifluoromethyl or chlorine,Y represents hydrogen or chlorine,R.sup.1 represents hydrogen or methyl andR.sup.2 represents formyl or the radicals of the formulae ##STR2## in which R.sup.3 represents alkyl with 1 to 4 carbon atoms, or the two radicals R.sup.3 together represent an alkylene chain with 2 or 3 carbon atoms,R.sup.4, R.sup.5, R.sup.6 and R.sup.7 independently of one another represent hydrogen or alkyl with 1 to 4 carbon atoms,m represents 1 or 2,n represents 0 or 1 andZ represents trimethylsilyl, optionally substituted azolyl which is bonded via nitrogen or the radicals of the formulae ##STR3## in which R.sup.8 represents alkyl with 1 to 4 carbon atoms,or the two radicals R.sup.8 together represent an alkylene chain with 2 or 3 carbon atoms,R.sup.9 represents alkyl with 1 to 4 carbon atoms,X.sup.1 represents oxygen or sulphur andR.sup.10 and R.sup.11 independently of one another represent hydrogen or alkyl with 1 to 4 carbon atoms,and their use as herbicides.