Watson, G.W. and E.B. Himelick
Root distribution of nursery trees and its relationship to transplanting success
Journal of Arboriculture 8(9): 225-229
The natural root distributions of seven species of shade trees (Norway, red and sugar maple, green ash, redbud, ginkgo, and pin oak), growing under nursery conditions were characterized. The north quadrant of the root systems of these trees was more developed than any other quadrant. In general, the vertical distribution of the major roots showed the greatest development at the soil depth of 13-38 cm, with limited growth in the top 12 cm, and decreasing development at depths below 38 cm. The fibrous root densities were usually greater in the upper 10 cm depth than at the lower depths. Tree spades, commonly used to transplant nursery trees, reduce the root system by up to 98 percent. Since regenerated roots originate primarily at the severed ends of the roots cut during digging, location of these severed roots with respect to the new soil is an important factor in re-establishment of transplanted trees.