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3 Signs of Bacterial Leaf Scorch on Your Oak Tree

3 Signs of Bacterial Leaf Scorch on Your Oak TreeAutumn is a time to enjoy the beautiful changing colors of the trees, with leaves transforming from green to shimmering shades of red, orange and yellow. But the leaves on many Oak Trees in the Philadelphia area are turning straight to brown and the color change is happening much too early. The cause of this is Bacterial Leaf Scorch, an infection that spreads easily and can kill an Oak if it’s not treated! The experts at Giroud Tree and Lawn share the 3 signs of Bacterial Leaf Scorch so you’ll know what to look for on your Oak Trees!

What is Bacterial Leaf Scorch?

Bacterial Leaf Scorch is a serious, often fatal disease that infects many trees, and it is most prevalent in Oaks. This infection is spread from tree to tree by leafhoppers, a tiny leaf eating insect. Once infected, the vessels of the tree become clogged with a bacterium that spreads throughout the tree. Without treatment, Bacterial Leaf Scorch will kill a tree. Giroud’s ISA Certified Arborists use an antibiotic called Oxytetracycline to treat trees infected with Bacterial Leaf Scorch.

“There is no cure for Bacterial Leaf Scorch,” says Drew Slousky, Giroud Vice President and ISA Certified Arborist.  “However, treatment with Oxytetracycline can dramatically improve a tree’s chances of survival.” 

Seen in Fall, Treated in Spring

If your tree is infected with Bacterial Leaf Scorch, treatment must be applied in early Spring when the bacteria is most vulnerable. However, the only time you can see the symptoms of this infection is in late summer to early Fall. To the untrained eye, the symptoms are easy to miss. You might think that your tree is simply transitioning with the changing seasons. Here are Giroud’s 3 Signs of Bacterial Leaf Scorch: 


  1. Premature Leaf Color Change
  2. Early Leaf Drop
  3. Leaves with a Burned Appearance

Bacterial Leaf Scorch is most common in all species of Oak Trees. However, it can also infect Elms, Sycamore, Mulberry, Sweetgum, Sugar Maple, and Red Maple.

Jeanes Hospital: A Bacterial Leaf Scorch Treatment Success Story

The proof is in the results! Giroud treated the Oaks at Jeanes Hospital in Philadelphia for Bacterial Leaf Scorch for several years. With antibiotic treatments of Oxytetracycline, these Oaks display full crowns of lush green leaves. Conversely, just across the street, untreated Oaks show severe Bacterial Leaf Scorch decline.

Check out Giroud’s video to see the amazing comparison of treated Oaks versus untreated Oaks!

How a Tree Infected with Bacterial Leaf Scorch Benefits from Deep Root Feeding

Almost any tree can benefit from deep root fertilization, but it’s even more critical for a tree infected with Bacterial Leaf Scorch.  Injecting fertilizer deeply into the soil near a tree’s roots gives your tree the added strength it needs to fight the infection and promote strong root growth. Giroud uses a slow release fertilizer that delivers biostimulants and critical nutrients for up to 12 months. 

What Happens if You Choose Not to Treat Bacterial Leaf Scorch

There is no doubt that, if left untreated, a tree infected with Bacterial Leaf Scorch will eventually die. While losing a valuable element of your landscape is frustrating, the damage a sick tree can do to your property can be even more upsetting! Large limbs that dry out from lack of proper water circulation can break off and fall on to roofs, garages, cars and playsets. A sick tree is significantly more susceptible to storm damage, especially freezing winter storms and during hurricane season when winds can reach over 30 miles per hour. By not treating a tree infected with Bacterial Leaf Scorch, you are putting your property at risk!

Why Should You Hire a Certified Arborist to Care for Your Oak Trees?

There is no cure for Bacterial Leaf Scorch, but an ISA Certified Arborist will have the know-how to treat your trees with the correct antibiotic and the appropriate amount of it. Check out Giroud’s informative video of Plant Health Care Manager, Rodney Stahl, performing an injection to combat Bacterial Leaf Scorch:



It’s important to ask the right questions when choosing a tree service company to treat your trees. You’ll want to ask about their experience, their credentials, and for recommendations from their customers.

It All Starts with an Inspection by an ISA Certified Arborist

Giroud’s ISA Certified Arborists have a wealth of experience and training to properly diagnose and treat all species of trees! 

Call 215-682-7704 today to schedule a FREE Inspection for your trees! 


Author: Jeanne Hafner

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