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Be Careful Cutting Your Roots

What you don’t know can kill a tree

Did you know that only roots less than one inch around are capable of generating new roots from the cut end? Did you know that the cut end of a small root can only grow three new roots at the most?
    Roots are not like branches. When you prune away the end of a branch, you stimulate the development of side branches. Root regeneration only occurs at the ends of the cut root.
    Root pruning is common in commercial nurseries where large trees are grown in the ground. Root pruning starts when the seedlings or rooted cuttings are first planted in the field, always after woody plants have stopped producing new leaves in the first flush of growth. It works to stimulate multiple branching of roots as close to the stem as possible so when the plant is dug and transplanted into your landscape, it will have a better chance of survival. Roots are typically pruned every two years with greater distance from the trunk each time.
    It’s done by making a circle of deep cuts at the plant’s drip line, severing the roots with a sharp spade.
    Root pruning during shoot elongation and leaf growth often results in severe wilting and loss of foliage, thus weakening the plant.
    However, there comes a time when the plants become too tall or wide and root pruning is no longer feasible. If root pruning were delayed until pruned roots are larger than one inch in diameter, many trees would die because large diameter roots are unable to generate new roots.
    So you take a risk when you decide to dig up a well-established plant to move it or cultivate a plant from a wooded area for transplanting into your landscape. Pruning away branches to achieve a balance between the top and the loss of roots only makes matters worse.
    Large roots can be stimulated to generate new roots by inserting toothpicks into the sides of larger cut roots. Soak wooden toothpicks in a concentrated solution of rooting hormone. Wearing latex gloves, use an icepick to pierce a hole in the side of the root and insert a treated toothpick into the hole. The rooting hormone in the treated toothpick will stimulate new roots to grow from the side of the large roots.