Abstract: A method of stimulating the growth of roses, particularly in greenhouses, by applying to the rose bushes N,N-di-n-propyl-4-trifluoromethyl-2,6-dinitroaniline, known generally as trifluralin, in combination with 2,4-dichlorophenoxyacetic acid (2,4-D). The method also comprises applying trifluralin and 2,4-D in combination with cacodylic acid.