APPENDICES - Laserfiche WebLink

Introduction The quality of nursery stock has lasting effects on tree longevity, highlighting the importance of nursery stock inspection and selection. This appendix visually displays the nursery selection BMPs and provides explanations on why this practice is important for tree longevity. Table of Nursery Stock Characteristics Characteristic Reasoning Relation to Longevity Root ball Inspect root ball to ensure roots are white in color. Healthy roots are necessary for tree roots to efficiently absorb water and nutrients and provide the entire tree with resources for tree growth and health. Reject stock that have roots with a sour smell. Remove girdling roots at the time of planting or reject stock. Girdling roots restrict the tree’s water and nutrient flow from roots to the rest of the tree reducing growth and health. Ensure structural roots are horizontal and reach the root ball periphery. Trees with horizontal roots and balanced root structure enable the roots to access larger soil areas which may contain more nutrients and water to provide to the tree. Branching structure Look for specimens with a strong, central leader, branch aspect ratio less than 1/3rd of the trunk for each primary branch, with even branch distribution both radially and vertically. Trees with optimal structure will have less defects to correct as the tree establishes into landscape. When trees are pruned or corrected for defects at the time of planting, trees need resources to compartmentalize the wound and heal. By avoiding these defects, trees will be able to establish without a need for greater resources including water. Quality of stock Trees should be healthy and vigorous with no signs of drought stress, die-back, pest or disease, and no signs of mechanical injury. Healthy trees with no signs of stress establish into the landscape more readily.