Branch Flagging in Trees: Causes, Treatment, and Prevention

Branch Flagging in Trees: Causes and Treatment

What is Branch Flagging?

Branch flagging is a condition that occurs when some of a tree’s branches turn brown, wilt, or die. These affected branches are usually scattered throughout the tree’s crown, rather than grouped together.

Causes of Branch Flagging

There are several different causes of branch flagging in trees, including:

• Cicada damage: Cicadas are insects that can damage young tree branches by laying their eggs in them. This damage can cause the branches to break off and fall to the ground.
• Kermes scales: Kermes scales are small, brown insects that attach themselves to tree twigs and suck their sap. This can damage the twigs and cause them to die.
• Twig girdlers and twig pruners: These are types of beetles that attack oak, hickory, and other hardwood trees. They can damage twigs by girdling them (cutting off their bark) or pruning them off entirely.
• Botryosphaeria canker: This is a fungal disease that can affect oak twigs, causing them to bend inward and turn brown.
• Thousand cankers disease: This is a serious invasive pest that damages black walnut trees. It can cause the tree’s branches to die and eventually kill the tree.

Treatment for Branch Flagging

The treatment for branch flagging depends on the cause of the problem.

• Cicada damage: Prune out the affected branches when the tree is dormant and burn the detritus.
• Kermes scales: Treat with appropriate insecticides.
• Twig girdlers and twig pruners: Rake up and burn all fallen twigs and branches to limit their populations.
• Botryosphaeria canker: This condition is not serious and usually does not require treatment.
• Thousand cankers disease: This condition may require special treatment. Take a sample of the flagging to your garden store for advice.

Preventing Branch Flagging

There are a few things you can do to help prevent branch flagging in trees:

• Inspect your trees regularly for signs of damage or disease.
• Prune out any dead or diseased branches.
• Keep your trees healthy by watering them regularly, fertilizing them, and mulching around them.
• Avoid planting trees in areas where they are likely to be exposed to pests or diseases.

By following these tips, you can help keep your trees healthy and free from branch flagging.