Abstract Experiments were conducted during the summer and fall to evaluate the effects of various concentrations of chlormequat chloride, ancymidol, BAS 106, and SD8339 on the height and plant quality of potted Dianthus cultivars ‘Snowfire’, ‘Indian Carpet’, and ‘Persian Carpet’. The effects of the growth retardants on the height and number of vegetative shoots were extremely diverse. The greatest height reduction was from BAS 106 applied at 3.6 mg a.i. per plant. As a result of this treatment, ‘Snowfire’ height was reduced by 70.0%, ‘Persian Carpet’ by 42.7%, and ‘Indian Carpet’ by 67.3%; however, both BAS 106 and SD8339, applied at concentrations that significantly reduced plant height, resulted in severe foliar damage. Chlormequat chloride and ancymidol reduced the height of ‘Snowfire’ at all treatment levels. ‘Snowfire’ height was reduced by 16.4% with 3000 ppm of chlormequat chloride and 47.5% with 144 ppm of ancymidol. Initial phytotoxic damage on ‘Snowfire’ from chlormequat chloride and ancymidol was not evident at the time of harvest. Chlormequat chloride and ancymidol applied to ‘Persian Carpet’ and ‘Indian Carpet’ in amounts to reduce plant height significantly resulted in severe foliage damage. Chemical names used: 2-chloro-N,N,N-trimethylethanaminium chloride (chlormequat chloride); α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); 5-(4-chlorophenyl)-3,4,5,9,10 pentaaza-tetracyclo-5,4,102,6,08,11-dodeca-3-9-diene (BAS 106); and N-(phenylmethyl)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (SD8339).