The responses of photosynthetic cotton seedlings to suboptimal spring temperatures have two aspects, level of growth inhibition and extent to which stressed seedlings recover from exposure to chilling. Significant cotton cultivar differences in sensitivity to suboptimal temperatures and in responses to calcium as a stress preventative or ameliorant have been documented. Cotton cultivars also differed in level of recovery after suboptimal temperature stress, suggesting that calcium might improve recovery capacity. Exogenous calcium (0.1, 1.0, or 10 mM) was applied to the roots of 2-day 31 C-grown cotton seedlings that were grown through Day 8 at 10, 15, 20, 25, 30 or 35 C before transfer to 30 C, 48 h prior to harvest on Day 10. Growth of all three cultivars was increased by calcium, 'Deltapine 61' and 'Paymaster 145' showing the greatest calcium-induced recovery effects. 'Coker 315' was the least sensitive to suboptimal temperatures and was least affected by added calcium. In Coker 315 and Paymaster 145, root growth was more promoted by calcium. Calcium-induced promotions of Deltapine 61 root and shoot growth were equal. Calcium altered the root:shoot length and relative water content ratios in recovering seedlings. Increased stress recovery induced by calcium in cotton cultivars sensitive to postemergent suboptimal temperatures indicates that application of calcium can aid in rapid growth resumption when weather conditions return to normal after a period of suboptimal spring temperatures.