Impacts of Wire Basket Retention and Removal on Whole Tree Stability and Long-term Growth1

Abstract

When balled-and-burlapped trees are planted, a decision must be made regarding whether the wire basket, burlap, and other packing materials should be removed (completely or partially) or retained. While past research has failed to show a significant impact of either approach with regard to initial growth and establishment, many professionals still question whether a decision to leave the wire basket intact at planting will have longer-term impacts to tree health and stability. In this study, we revisit two nursery trials first initiated in 2011 and 2012 to assess the impact of burlap folding, and full wire basket removal, partial removal, or retention on tree growth and root anchorage five to six growing years after planting. We found that neither stem caliper (min P = 0.249) nor twig elongation (min P = 0.297) differed among removal treatments with the Norway maple (Acer platanoides L.) and ‘Skycole' honeylocust (Gleditsia triacanthos L. var. inermis) trees used in this study. Similarly, we were unable to detect any differences in rooting strength among the removal treatments tested (min P = 0.154). These results serve as further evidence that wire baskets are not a cause of early tree mortality or instability. Index words: Arboriculture, biomechanics, growth and longevity, nursery production, static-pull test, transplanting, transplant shock. Species used in this study: Norway maple (Acer platanoides L.); ‘Skycole' honeylocust (Gleditsia triacanthos L. var. inermis).