Use of the computer and specialized software can provide flexibility needed to develop management schedules for landscape sites that differ in geographic location, size, and maintenance level. The major problem faced in developing this software is accommodating different climates and year-to-year variations in weather, which influence the optimum timing of many management activities. Using phenological observations of common plants to time maintenance activities rather than relying entirely upon calendar dates was investigated as a solution t this problem. A program that used a combination of phonological observations and calendar dates to schedule maintenance activities was developed. A system of maintenance activity modules and landscape plant categories was used to produce a program flexible enough to be useful for a variety of landscape sites. This modular approach also permits future expansion of the program to include additional maintenance activities.