Castor (Ricinus communis) has been cultivated for millennia as a source of oil. Recent federal initiatives calling for development of production practices for crops with biofuel potential have prompted studies in castor. Significant advantages of castor compared to other oilseed crops include extremely high oil content, nematicidal effects of castor, high seed yield, and the superior quality of the oil/diesel produced. Most U.S. castor has been cultivated in the High Plains of Texas and the Mid-west. Both these areas require supplemental irrigation for maximum seed yield. In addition, plant spacing within-the-row of 3 plant per meter are recommended primarily for water considerations. Castor production in the humid southeastern U.S. would be expected much different. A study was undertake to determine optimal row spacing or population density of castor plants cultivated in north-central Mississippi. A factorial of four row spacings and four population densities with four replications was established using two cultivars (Hale and Lynn). During the course of the growing season, observations were made on date of specific raceme development. Yield was taken on each plot at the end of the growing season. The results were based on a single year's observations.