Root-pruning technique

Steve and Val Bradley explain an alternative way of pruning to keep plants in check

- Steve and Val Bradley

ROOT pruning is a technique that has fallen from favour and you seldom see it practised today, but it is very effective when done correctly. It is a method of exposing and removing root sections from a live plant in order to control its growth or prepare it for being moved.

Root pruning works because there must be balance between the root system of the plant and the upper part – the shoots and stems. The chemicals that occur in each must be in balance for the plant to grow, so by removing sections of root, the manufacture and supply of these chemicals (cytokinins) is restricted. This, in turn, restricts the chemicals (auxins) responsible for the development and extension growth of stems and branches.

Pruning isn’t the only option

Many gardeners believe that the only way to slow the growth rate of a tree or shrub is to reduce the amount of shoot growth (pruning) on a regular basis to keep the plant in check and stop it getting too big. However, there are other alternatives, including, as we demonstrated a year ago, the technique of bark ringing to restrict the sap flow, which can have a significant effect on slowing the shoot growth of a woody plant.

Encouraging new roots