Field trials to study the growth and biomass production of Leucaena leucocephala and Vitex negundo in relation to their age and season of harvesting were conducted on alkaline soils of North Indian plains under irrigated conditions. Both shrubs showed excellent regeneration and survival ( > 90%) of coppiced stumps. Increasing the harvest age from 10 months (in February) to 18 months (in October) did not result in statistically significant increase in biomass production of Leucaena. The yield on per plant and unit area basis was higher in coppiced stands than original stands of Leucaena and Vitex. The highest increase in biomass production of Leucaena was recorded between 18 and 20 months harvesting age. Harvesting in December was found the best for Leucaena. Vitex registered rapid growth during the period from summer untill the rainy season. The post-harvest conditions for coppice development, the period of rapid growth and the physiological stage at harvesting interacted significantly with the growth and biomass production of these shrubs. (C) 2003 Elsevier Ltd. All rights reserved.