Chrysanthemum plants (Chrysanthemum morifolium Ramat. cv. Bright Golden Anne) were grown in 3 potting mixes, perlite alone, peat moss/perlite and peat moss/loam (both 1:1 by volume) and irrigated 1 or 5 times/day or as needed with nutrient solutions with or without urea peroxide. No significant differences were noted in leaf area, fresh and dry weights due to peroxide treatment in the peat moss/loam or perlite mixes. Urea peroxide-treatment in peat moss/perlite mix increased leaf areas, fresh and dry weights when watered 1 or 5 times per day. Plants receiving urea peroxide had large, dark green leaves with little evidence of the effects of overwatering while controls exhibited a mottled chlorosis, especially on older leaves.