Pruning will produce high-value sawlogs free of knots.
Knots are branches that become incorporated into the trunk as it grows. If a branch is removed, all the new growth over the wound is knot-free. This knot-free wood is known as clearwood which produces high-grade timber for furniture, panelling and veneers.
The aim of pruning is to produce logs where the knotty core is restricted to a diameter of 10-15 cm, and is surrounded by a large sheath of clearwood.
Growing trees close together keeps branches small and produces suitable grades of timber. The disadvantage of close spacing is that trees grow slowly and it takes a long time to produce sawlogs. Trees grown at wide spacing grow quickly but also develop large branches. Pruning is therefore essential to obtain high quality wood from widely spaced trees.
The form of a young tree can also be improved by removing faults such as forks and large branches.
When removing branches it is important not to damage the wrinkly wood around the base of the branch (the collar). This contains tissue which produces new wood cells. If too much of it is removed or torn the pruning will take longer to heal and expose the tree to fungal attack, as well as lowering timber quality.
Pruning tips
Abstract from TreeNote No. 4 (Revised July 1998) Department of Agriculture, Western Australia
Pruning trees for sawlogs
Knots are branches that become incorporated into the trunk as it grows. If a branch is removed, all the new growth over the wound is knot-free. This knot-free wood is known as clearwood which produces high-grade timber for furniture, panelling and veneers.
The aim of pruning is to produce logs where the knotty core is restricted to a diameter of 10-15 cm, and is surrounded by a large sheath of clearwood.
Growing trees close together keeps branches small and produces suitable grades of timber. The disadvantage of close spacing is that trees grow slowly and it takes a long time to produce sawlogs. Trees grown at wide spacing grow quickly but also develop large branches. Pruning is therefore essential to obtain high quality wood from widely spaced trees.
The form of a young tree can also be improved by removing faults such as forks and large branches.
When removing branches it is important not to damage the wrinkly wood around the base of the branch (the collar). This contains tissue which produces new wood cells. If too much of it is removed or torn the pruning will take longer to heal and expose the tree to fungal attack, as well as lowering timber quality.
Pruning tips
- prune close to the trunk to avoid stubs/coat hangars which take a long time to heal
- use sharp equipment for fast, clean cutting to reduce damage to the 'collar';
- only prune branches where trunk diameter is at least 10 cm
- leave more than 50 per cent of the crown for continued growth and to protect the tree from wind damage.
- premature pruning wastes time and effort, and slows tree growth unnecessarily.
- Delayed pruning results in large losses of valuable clearwood
- remove branches before they exceed 2.5 cm diameter - large branches are difficult and expensive to remove.
- prune branches while they are still alive and green.
- Prune in autumn and early winter as spring or summer pruning places trees under greater stress
Abstract from TreeNote No. 4 (Revised July 1998) Department of Agriculture, Western Australia
Pruning trees for sawlogs