Many greenhouse managers do not fully comprehend the relationship between crop fertility and ground water pollution, and impacts of fertility on pest & disease. Better management of fertilization improves crop quality and reduces nutrients lost to the ground(water). We tested pH and soluble salts weekly during the Poinsettia growing season, and sent off soil and foliar samples to Peters for lab analysis. In general, the growers highly valued the project because cultural errors were caught early. Several of them will continue the monitoring in the future; the others would like a professional to do it for them. We need to extend understanding of the importance of monitoring nutrient solutions to other greenhouse operations, and also to revise the Poinsettia crop production guide for New York.