Skip to main content

Are there magnolia trees growing in your yard? Have you taken a good look at the branches or leaves lately? It might be worth closer inspection, especially this time of year.

The past several weeks our arborists have logged dozens of phone calls from customers asking about colorful bumps – some white, pink-orange or brown – coating the branches of their magnolia trees. These bumps are actually insects called magnolia scale, a half-inch long pest that attacks trees by sucking out their fluids and sap.  The insects leave behind blackened leaves and a chalky substance on branches. They even have the potential to kill or severely disfigure magnolia trees.

A magnolia scale outbreak is known to occur during July and August in many parts of North America. A mature insect lays eggs on trees over the summer, giving birth to additional crawlers in late summer. There are effective treatments. Applying systemic insecticides and contact insecticides during these final weeks of summer is recommended to kill off active scales and their offspring. A dormant oil spray should be made early next spring for further control in the following year.

The magnolia scale outbreak serves as a good reminder to follow a Plant Health Care program. Being proactive about tree care can help spot early signs of trouble, fend off emergency treatments, avoid unnecessary removals and save up to hundreds and even thousands of dollars in expenses.

Be sure to look for tree care experts certified by the International Society of Arboriculture (ISA), for a year-round service plan based on immediate tree care needs and the long-term goals for your landscape.