Tree Root Pruning
Root pruning may be required to restrain trees in small gardens, or encourage fruit trees to flower.
What happens in the latter case is: the trees become less vigorous which encourages the formation of flowers rather than leafy growth.
Mature trees are less resilient than young trees and should not be root pruned.
Root pruning should be carried out in winter when the trees are dormant.
Depending upon the situation, the procedure should be done over two years, to prevent stressing the tree too much, i.e. do 50% of the pruning in the first season, and the remainder the following season.
Form a trench approx 300-400mm (12”-16”) deep, and 600-1200mm (24”-48”) diameter, from the trunk of the tree and carefully fork the soil away from the roots to avoid damaging the fine fibrous ones.
Tie the thin, whippy roots out of the way before sawing off the thicker ones.
Pare any roughened wound edges with a sharp knife and apply a proprietary wound dressing.
Once pruning is complete, replace some of the soil and lay the lower fibrous roots over the base of the trench.
Continue in the same fashion, gradually treading the soil down as you go.
After treatment ensure the tree is kept well watered thus reducing the potential for further stressing.
Inserting a spade to its full depth around the tree to cut surface roots is a less-severe way of root pruning.