Why Is My Tree Leaking Sap?

Sap leaking out of tree

If you've ever walked through a park or forest, you've likely encountered trees that appear to be leaking a sticky substance. This phenomenon is called tree sap leakage, and it can be both fascinating and concerning for tree owners and caretakers. Tree sap is a vital part of a tree's life, as it carries nutrients and water throughout the plant. However, when sap begins to leak from the tree, it can be a sign that something is wrong. In this article, we'll explore the common causes of tree sap leakage, treatment options for leaking trees, and preventative measures you can take to keep your trees healthy and sap-free.

Common causes of tree sap leakage

The most common cause of trees to leak sap is physical damage to the tree (often from garden tools), causing sap to leak as the tree attempts to heal itself. Other causes are insect infestations (such as bark beetles infestations), or disease. 

Physical damage

Physical damage can occur when a tree is damaged by lawn equipment or garden tools, or even when a branch breaks off due to heavy snow or ice. Excessive pruning can also cause sap to leak.

Insect infestations

Another common cause of tree sap leakage is insect infestations. Certain insects, such as aphids, scale insects, and bark beetles, can feed on tree sap and cause it to leak out of the tree. These pests can cause significant damage to trees, often leading to an overall decline in the tree's health.


Diseases can also cause sap leakage in trees. Fungal and bacterial infections can invade a tree's vascular system, causing it to leak sap. In some cases, these diseases can be fatal to the tree if left untreated. Common tree diseases that can cause sap leakage include cankers diseases, bacterial wetwood, and slime flux.

Treatment options for leaking trees

Pruning and wound care

If your tree is leaking sap due to physical damage, the first step is to assess the extent of the damage. If the damage is minor, you can help the tree heal by carefully pruning away damaged branches and applying a tree wound dressing to the affected area. Be sure to sanitize your pruning tools before and after use to prevent the spread of disease.

Insect control

For trees leaking sap due to insect infestations, it's essential to identify the culprit and take appropriate control measures. In some cases, this may involve applying insecticidal soap or horticultural oil to the affected area. For more severe infestations, you may need to consult with a professional arborist to determine the best course of action.

Disease management

If your tree is leaking sap due to a disease, it's crucial to identify the specific disease and take steps to manage it. This may involve applying fungicides or bactericides, removing infected branches, or in extreme cases, removing the entire tree to prevent the spread of the disease to other trees.

Effects of sap leakage on tree health

Stress and vulnerability

When a tree is leaking sap, it can be a sign that the tree is under stress. This can make the tree more vulnerable to other issues, such as insect infestations and disease. 

Loss of nutrients and water

As sap carries essential nutrients and water throughout the tree, significant sap leakage can lead to a loss of these vital resources. This can cause the tree to become weak and more susceptible to other issues, such as drought stress and poor growth.

Potential for decay

If sap leakage is caused by damage to the tree's bark or branches, it can create an entry point for decay-causing fungi and bacteria. Over time, this decay can weaken the tree's structure and potentially lead to branch or tree failure.

Preventative measures for tree sap leakage

Proper tree care

One of the best ways to prevent tree sap leakage is to practice proper tree care. This includes regular pruning to remove damaged or dead branches, watering during periods of drought, and applying appropriate fertilizers and soil amendments to ensure your tree has the nutrients it needs to thrive.

Monitoring for pests and diseases

Regularly inspecting your trees for signs of insect infestations and disease can help you catch issues early before they lead to sap leakage. Familiarize yourself with the common pests and diseases that affect trees in your area and take action at the first sign of trouble.

Protecting trees from damage

To prevent sap leakage caused by physical damage, you're best avoiding excessive pruning, and also being cautious when working around trees with tools and equipment.

When to consult a professional arborist

While many cases of tree sap leakage can be addressed by homeowners, there are times when it's best to consult a professional arborist. If you're unsure of the cause of the sap leakage, or if the issue is severe and beyond your ability to manage, a professional arborist can help diagnose the problem and recommend appropriate treatments. Additionally, if your tree is suffering from a serious disease or insect infestation, a professional arborist may be necessary to properly manage the issue and prevent further damage to the tree.

Conclusion: Protecting your trees from sap leakage

Tree sap leakage can be a concerning issue for tree owners and caretakers, but with the proper knowledge and care, it can often be managed and prevented. By understanding the common causes of sap leakage, taking appropriate treatment measures, and practicing preventative tree care, you can help ensure that your trees stay healthy and thrive for years to come. And when in doubt, don't hesitate to consult a professional arborist for guidance and assistance in managing and preventing tree sap leakage.