Root Pruning

Root pruning is generally done when a tree is being transplanted or the roots are causing damage to a nearby structure. It can also be used to maintain a dwarfed tree size and in some cases to encourage the flowering of fruit trees.

Why should a tree’s roots be pruned?

  • When you are transplanting a tree

  • To improve the health of the tree

  • When roots are invading nearby structures, sewer lines, or septic tank drain fields

  • To minimize root damage during a home construction project

Root pruning does not damage the tree or shrub, but it will stress it. To give the plant time to recover before being dug, root pruning should ideally take place six months to a year before digging and transplanting the tree which gives the new roots time to grow.

When should roots be pruned?

  • Trees and shrubs destined for spring transplant should be root pruned in the autumn

  • Those to be transplanted in fall should be pruned in spring

The process begins by excavating the roots using an air spade, hydro excavation and/or hand tools to expose the roots. This exposure allows us to evaluate the best places to cut, preferably beyond sinker roots or junctions. Roots can be cut most cleanly with a sharp saw or lopper. Exposed fine roots that are to be preserved may be covered with burlap and sprayed with water, or they can be sprayed with a hydrated, fine, water-holding gel to prevent desiccation.

Following root pruning, soil moisture and the tree’s overall health’s should be monitored frequently. Root pruning should not be done immediately prior to or during a drought period and irrigation should be applied prior to and after root pruning if there is not adequate rainfall. Monitoring for secondary pests such as borers and applying fertilizer and soil amendments based on soil analysis will help to assure a positive outcome. Proper mulching should be applied to reduce soil moisture loss and promote root growth.

A tree risk assessment should be performed prior to cutting any roots and a plan formulated to consider the best techniques for optimal success.