Accurately assessing crop growth stage and knowing the sequence and timing of developmental events directly, or relative to other events or processes occurring in the plant, are critical for making appropriate crop management decisions and for creating advanced management practices that exploit modern genetic potential and sustain the environment. In addition, thorough knowledge of the crop developmental sequence is critical for constructing more robust simulation models. The developmental sequence for winter wheat (Triticum aestivum L.) and other small grains was summarized several years ago and has served as a significant resource in developing simulations models with strong phenological underpinnings for these crops. This paper reports our continuing efforts to summarize the developmental sequence for maize (Zea mays L.). The sequence, gleaned from a broad literature search of both classic and modern reports and observation of maize, describes events from seedling emergence through physiological maturity. Associations between important meristematic events and outwardly visible events are highlighted and estimated using thermal time. How environmental stress, particularly water availability, alters the timing of developmental events is also considered. By compiling this summary from multiple reports, it represents a generic description of maize ontogeny and is of greatest use as a general description. As more is learned about the action of specific genes and gene interaction with environmental factors, we assume this general description will be tailored to depict development of specific hybrids or groups of hybrids so that robust simulations and targeted management practices can be created.