Not all tree diseases are fatal or even highly contagious. Often, minor disease pressures become more dangerous to a tree due to other cultural conditions. For example, a tree suffering from a lack of water or poor soil nutrition is more likely to suffer greatly from a minor disease. Although improving the watering and fertiliser schedule is needed, proper pruning can also help the tree recover its former health.
1. Remove Dead Wood
Dead wood serves no purpose in the crown of a tree, and it may actually harbour fungal spores or other disease organisms that can then continue to infect the neighbouring healthy areas of the tree. All dead wood in the crown must be removed with the wood cut back to the nearest living and healthy wood. Pruning cuts will be made at the base of the branch or at a leaf node, which will encourage healthy new growth.
2. Cut Out Disease
Living branches that are badly affected by the disease should also be removed. Much like dead wood, these are cut back to the nearest healthy wood. Depending on the type of disease and whether there are chemical treatments available, you may not need to remove branches with good growth that are only mildly affected.
3. Control Crown Size
A tree in recovery from disease or poor cultural conditions is more likely to suffer problems if it has an overly large crown to support. Reducing the overall size of the crown can aid in recovery. Crown reduction can also help remove disease since branch tips are often the first part of the tree to succumb to disease organisms. Cutting back all branches by a quarter to a third of their previous length reduces crown size without stressing the tree.
4. Allow Air Circulation
Air circulation throughout the crown is key to preventing and eliminating many fungal diseases. This is achieved by removing any branches with poor growth form, such as those touching or rubbing against a neighbouring branch. Branches that droop down, instead of growing horizontally or gently angling upward, can also be thinned out to help open the crown to more air circulation.
5. Practice Good Sanitation
All pruning of a diseased tree must be accompanied by proper sanitation so the disease isn't spread about. This includes cleaning all pruning tools with a disinfectant following pruning, as well as picking up and disposing of all branches and twigs that were removed during the trim.
Contact a tree pruning service if you would like more help with a sick tree.