Dealing with Borers in Plum Trees: Identification and Treatment

If your plum tree is oozing sap and showing dieback on branches, you’re likely dealing with borers. These insects tunnel beneath the bark, disrupting the tree’s vascular system and causing the characteristic sap formations you see on the trunk and limbs.

Confirming the Problem

The presence of sticky, sap-like globules on the bark—especially when accompanied by wilting or dying branches—is a classic sign of borer activity. The insects feed inside the wood, pushing frass and sap out through entry holes.

Immediate Mechanical Control

For a small infestation, you can physically kill the larvae by inserting a thin wire or sewing needle into each entry hole. This method is chemical-free and effective if you catch the problem early.

Chemical and Organic Options

• Systemic insecticides (such as those containing imidacloprid) are taken up by the tree and kill borers as they feed. Apply according to label directions.
• Atomic Grow is an organic product that boosts the tree’s natural defenses and can help deter borers without synthetic chemicals.

Prevention Tips

Keep your plum tree vigorous with proper watering, mulching, and fertilization. Healthy trees are less attractive to borers. Remove and destroy any severely infested limbs to reduce the local population.