Cypress Canker: When To Lop And When To Chop
A tall, stately cypress tree can be a beautiful addition to any property. Unfortunately, these tropical conifer trees are vulnerable to a disease that has spread across wide areas of Australia in recent years.
Cypress canker, also known as cypress decline or cypress dieback, can rapidly kill the strongest and healthiest cypress trees. If a tree on your property has been infected with cypress canker, it is important to act swiftly -- to save the tree if possible, or to remove the tree safely if the canker is too advanced.
What Is Cypress Canker?
Cypress canker is a fungal infection, which enters trees through cracks in its bark and branch stumps left over after recent pruning. Once inside the tree, it causes severe damage to the cells that transport sap through a tree's trunk, roots and branches.
Sap in trees is analogous to blood in human beings; it transports moisture and nutrients around the tree. When cypress canker damages a tree's ability to circulate sap, the parts of the tree that are no longer receiving sap rapidly wither and die back.
Cypress canker kills every part of the tree above the infection site, as these areas of the tree are deprived of life-giving sap. For example, if the canker fungus enters the tree through a crack at the base of a branch, the branch will die from the tips of the branch down. If the trunk is infected, all the branches and trunk above the infection site are vulnerable to eventual dieback.
For the most part, cypress canker only infects trees of the cypress family, including both native and exotic species. However, it has also been known to affect tree species that are closely related to cypresses, including western red cedar and juniper trees.
If your cypress tree is showing signs of dieback, check for long, thin patches of dead bark. These cankers are generally found near the infection site. You may also see small, black growths on the bark — these are fungal fruiting bodies, and should not be touched.
Can Infected Trees Be Saved?
Unfortunately, the fungal species that caused cypress canker are highly resistant to fungicidal treatments, and there is no known cure for the disease. However, if the infection is caught early, and the infection site is not on the tree's trunk, it may be possible to save the tree with lopping.
Because cypress canker is highly infectious, you should call in a professional tree lopping service to do this job for you. The infected branches must be removed at their bases, and carefully disposed of to minimise infection risk. Professional services can use protective equipment and sanitisation procedures to prevent the fungus from spreading.
Once the infected branches have been lopped, your lopping service may recommend the removal of healthy branches on the opposite side of the tree. This helps to balance the crown, which is more aesthetically pleasing and distributes the tree's weight more evenly, preventing it from toppling during high winds.
What If The Tree's Trunk Is Infected?
If your tree service company finds that the tree's trunk is infected, the tree will almost certainly have to be removed. Leaving the tree standing can be very dangerous, as infected trees die at unpredictable rates, and may topple unexpectedly.
Once again, this job should be performed by trained tree service professionals taking special measures to prevent the fungus from spreading. Every part of the tree, including the stump and roots, will need to be removed, so your service may need to bring in excavation equipment and stump grinders to completely remove the infected tree.
Share