The purpose of this 5-year study was to investigate the effects of different cutting pressures (3, 6, 9, or 12 spears/plant) on aspargus harvested in spring or forced in July or August. `UC 157 F1' seedlings were transplanted in 1987 and clear-cut harvested1 from 1989 to 1993. Forcing plots were not spring-harvested, but allowed to produce fern in spring. Summer spear production was forced by mowing all fern and stalks at ground level on the 1st day of each forcing month. Harvested spears were graded and harvesting ended if either 1) 80% of the plants within each plot reached cutting pressure treatment levels or 2) 30 harvests had elapsed: Yields in 1989 were highest and equivalent for the following: spring-harvested at 9 to 12 spears/plant, July-forced at 12 spears/plant, or August-forced at 9 spears/plant. In 1991, forcing in July at 12 spears/plant yielded more than harvesting in spring or August at all cutting pressures. In 1993, August forcing at 9 to 12 spears/plant produced the highest yields with significantly lower yields from July forcing at all cutting pressures. The 1993 spring yields were very poor due to plant death. Stand losses from 1988 to 1993 were 60%, 40%, and 30% in spring, July and August plots, respectively. Cumulative yields over the 5-year-period were greatest and equivalent for July forcing at 12 spears/plant and August forcing at 9 to 12 spears/plant.