Ash Tree Oozing: Reasons For Ash Tree Leaking Sap

Many native deciduous trees, like ash, can leak sap as a result of a common bacterial disease called slime flux or wetwood. Your ash tree may ooze sap from this infection, but you might also see, coming from the bark, foaming white material that does not look at all like sap. Read on for information about why an ash tree is dripping sap.

Why is My Tree Leaking Sap?

The bacterial infection called slime flux results when bacteria grows inside a wounded tree. Several types of bacteria are implicated, although botanists have not identified a main culprit. These bacteria generally attack an ill tree or one that is stressed from too little water. Usually, they enter through a wound in the bark. Inside the tree, fermentation occurs from the bacteria and carbon dioxide gas is released. The pressure of the gas release pushes the ash tree’s sap through the wound. Sap spills out, making the outside of the tree trunk look wet. An ash tree leaking sap is very likely infected by these bacteria. This is especially true if there is foam mixed with the sap.

Why is My Ash Tree Oozing Foam?

The wet areas of sap on the outside of your ash tree become breeding grounds for other organisms. If alcohol is produced, the sap foams, bubbles and produces an awful smell. It looks like an ash tree oozing foam. You may see many different types of insects and insect larva coming to dine on the spilled sap and foam. Don’t be alarmed, since the infection cannot be spread to other trees by means of insects.

What to Do When an Ash Tree is Dripping Sap

The best offense in this case is a good defense. Your ash tree is far more likely to get infected by slime flux if it suffers from drought stress. In addition, the bacteria usually seeks a wound to enter. You can help the tree to avoid this infection by watering it regularly when the weather is dry. One good soaking every two weeks is probably enough. And take care not to wound the tree trunk when you are weed-whacking nearby. If, despite these precautions, your tree continues to ooze sap, there is little you can do to help the tree. Remember that most trees with slime flux do not die of it. A small infected wound is very likely to heal on its own.

Other Reasons My Ash Tree is Dripping Sap

Ash trees are often are infested by aphids or scales, both small but common insects. It is possible that the liquid you identify as sap is actually honeydew, a waste produce produced by aphids and scales. Honeydew looks like sap when it falls like rain from a tree badly infected with these bugs, coating bark and leaves. On the other hand, don’t feel you need to take action. If you leave aphids and scale alone, no grand harm comes to the tree and predator insects usually step up to the plate. Other insects affecting this tree, and possibly causing it to leak sap, include the emerald ash borer.

Teo Spengler

Teo Spengler has been gardening for 30 years. She is a docent at the San Francisco Botanical Garden. Her passion is trees, 250 of which she has planted on her land in France.