Application. Results of this study suggest that root wrenching of slash pine seedlings in the nursery can significantly improve ouplanting survival and subsequent growth at varied lifting dates. It has also been demonstrated that wrenched seedlings have greater tolerance to drying which could prove extremely valuable for seedlings commonly subjected to less than optimum establishment conditions. For improved slash pine survival, particularly when planting in stressed conditions, we recommend three root wrenchings initiated as soon as seedlings have reached desirable stem diameter.Abstract. Slash pine (Pinus elliottii Engelm.) seedlings were subjected to three wrenching treatments: One root wrenching in early August; Three root wrenchings in early August, September, and October; and No wrenchings. Seedlings were then lifted on five dates between November and February based on the number of chilling hours accumulated. All wrenched seedlings had reduced shoot dry weight, smaller shoot-root ratio, and smaller stem diameter and height. These morphological differences translated into improved survival as well as increased diameter and height growth when measured one and two years after planting. Only seedlings wrenched three times demonstrated improved root fibrosity. Furthermore, only multiple wrenched stock showed greater resistance to drying imposed prior to planting. At the time of lifting, seedlings lifted latest had greater stem diameter, increased root dry weight and number of root tips, and improved shoot-root ratio. However, no survival differences were detected across lifts, and those seedlings lifted earliest demonstrated the best height and diameter growth.Resumen. Plantas de semilla de Pinus elliottii Engelm. fueron sometidas a tres tratamientos de poda de rafz durante su estadfo en alm~icigo: 1) Una poda (a principios de agosto); 2) Tres podas (a principios de agosto, septiembre, y octubre); y 3) No podas. Las plantas fueron sacadas del vivero en cinco fechas, entre noviembre y febrero, despurs que acumularan un nfimero creciente de horas-frfo. Todas las plantas podadas tuvieron un menor peso seco de tallo y rafz, una menor proporci6n de tallo-raiz, y menor di~imetro y attura de tallo al momento del transplante. Estas diferencias morfolrgicas produjeron, a uno This paper is Journal Series No. R00695 of the Institute of Food and Agricultural Sciences, University of Florida, Gainesville 32611. 208 y dos afios despurs del transplante, una mayor sobrevivencia, y un mayor aumento en di~netro y altura que las plantas control. Solamente las plantas podadas tres veces aumentaron la fibrosidad en la rafz, y mostraron mayor resistencia cuando fueron sometidas a "estres" por desecacirn antes del transplante. Las plantas sacadas m~is tarde del vivero tuvieron mayor di~netro de tallo, mayor peso seco de ra/z, puntas de raiz m~is numerosas, y mejor proporci6n de tallo a raiz. Sin embargo, no hubo diferencias en la sobrevivencia de plantas sacadas a distintas fechas, y las transplantadas m~is temprano mostraron el mejor...