Ability to predict daily leachate volumes in greenhouse production enables strategic planning for the remediation of waste water. A case study greenhouse site (1620ft2) on Cornell campus was chosen because of the tile drainage system installed beneath. Roses `Sonya', `Royalty', and `Mary DeVor' were grown in 1170ft2 of bench and fertigated at bench level with automated spray nozzles. Data collection occurred over a 1.5 year period. Factors considered in modeling included: leaf area, irrigation and leachate volumes, and atmospheric / greenhouse environmental conditions (solar radiation, precipitation, temperature). Separate day and night models resulted, the night model included a condensation factor. Correlation existed between environmental factors, irrigation volume and leachate volume in the day model. In the night model a relationship between environmental factors and condensation was evident.