Bur oak blight
Tree & Shrub Disease

Bur Oak Blight in Southern Maryland

By Planet Friendly Pest Control·3 min read

Do you find it oddly satisfying to step on acorns from trees on your property? The Quercus Macrocarpa or bur oak is a common variety in Southern Maryland. Unfortunately, these beautiful trees are vulnerable to bur oak blight and many others.

If not correctly treated, it can kill the tree over time. Do you know what signs to watch for to identify bur oak blight disease?

Keep reading to learn how to recognize this disease. This guide will also discuss how it's treated.

01

What Is Bur Oak Blight?

Bur Oak Blight"˜s (BOB) is a native fungal pathogen called Tubakia iowensis. It only attacks the small-acorn type of bur oak trees (Quercus macrocarpa var. oliviformis). Experts believe higher average spring rainfall over the past 25 years is increasing the incidence rate.

02

Is BOB Harmful to Trees?

Bur oak blight leads to progressive and serious leaf browning and loss. The pathogen becomes stronger over many growing seasons.

This weakens the tree making it more susceptible to other problems. One example is Two Lined Chestnut Borer which often causes death.

03

Are You Located in a High Threat Area?

Experts have positively identified this pathogen in a variety of states. Examples include Arkansas, Illinois, Maryland, and Minnesota, to name a few. Be alert in the Southern Maryland counties of Charles, Calvert St., Mary's, and Anne Arundel.

The movement to other areas seems to be relatively slow. It's thought that BOB needs very specific conditions to develop and survive. This may help limit its spread.

04

What Symptoms Signal Possible Bur Oak Blight Fungus?

First, it's key to understand that a tree may show symptoms one year and not the next. Then you may find signs again the following year. Often, infections start in the lower part of the crown and then spread higher in future years.

It's common to initially see healthy-appearing leaves. Later in July, August, and September, brown spots and veins appear. Eventually, it covers the entire leaf and causes curling.

Any new growth in September will also die from the fungus. During the winter and early spring, these brown leaves stay on the tree.

In the summer, the petioles (the leafstalk) stay attached. Black fruiting bodies, or spores, grow at the petiole's base during the fall. These spores serve as carriers to reinfect the tree the next year.

05

Treatment For Bur Oak Blight

Today, scientists have developed effective treatments to achieve bur oak blight control. The expert injects a tree growth regulator regimen into the trunk.

The first treatment occurs between the initial leaf eruption and the first week of June. In late September to early October, it's injected again to protect it into the spring.

This regimen helps the Bur Oak tree withstand the stress of BOB. You may also see fewer affected leaves. Further fungicidal treatments or insecticides help decrease Two-Lined Chestnut Borer from developing.

Ask the tree expert about the environmental safety of the chemicals they use. Choosing eco-friendly products reduces the negative impact on our planet.

06

Are You Noticing Tree, Shrub, or Pest Problems?

This article provided an overview of b

bur oak blight

Written by

Planet Friendly Pest Control

Eco-conscious pest control for homes with pets across Southern Maryland & Northern Virginia — serving local homeowners since 2010.....

All articles

Happy Customers

Homeowners who made the switch

Hundreds of Google reviews across our verified service locations.

Excellent on Google

5.0
  • Josh F.

    Google review · Sep 2026

    Alex was great! Very professional and explained the whole process before doing any work. We had a wasp nest in our wall, getting in through a seam between our brick and siding. I thought it would be a costly problem, but it was taken care of in about 15 minutes.

  • Amy B.

    Google review · Sep 2026

    I am very pleased with the work of Planet Friendly Pest Control. I had a large wasp nest in the garage and they came out to treat it the same day! The process was clear and professional. I was told the price when I called and they didn't try to upsell me on a monthly or quarterly contract. As mentioned above, they came out the same day I called and they texted me when they were on their way. They treated the nest and then came back a week later to confirm it was taken care of and removed the nest. It's now been a couple of weeks since the initial visit and no sign of new wasps! I would not hesitate to use them again.

  • Nicholas V.

    Google review · Sep 2026

    Excellent service and full explanation of service

  • Jfk

    Google review · Sep 2026

    Great service. Wasps eradicated the next day.

  • Cheryl P.

    Google review · Aug 2026

    Tech was very nice, explained what the chemical is designed to do.

  • Patrick H.

    Google review · Jul 2026

    I want to sincerely thank Planet Friendly Pest Control and its owner, Gene Wright, for their immediate response and action to deal with a hive of Bald Face Hornets who, unbeknownst to me, had taken home in a fair size shrub at the back of my house. As I attempted to trim the shrub, I was swarmed by Hornets and stung 8 or 9 times before I could get to safety. I left my tractor and tools in a hurry and was afraid to retrieve them until the bee issue was addressed. Again, PFPC responded quickly and allowed me to get my tools and continue my recovery from the bee stings. I considered the price to be very fair for the treatment of the issue at hand and the sharing of knowledge to avoid further such mishaps. I will only call PFPC when in need of pest control.

  • Jason M.

    Google review · Jul 2026

    Gene was honest and thorough.

  • Betty E.

    Google review · Jul 2026

    Roger came out and killed hornets in large nest on our house. It was taken care of the day after I called for service.

  • Joyce

    Google review · Jul 2026

    Joshua was Friendly and efficient.

  • Ken C.

    Google review · Jun 2026

    Planet Friendly has been doing our pest control for several years now. They are reliable, and perform a great service for us. We are notified by email when the appointment is confirmed. They are always professional and knowledgeable.

  • Nikole R.

    Google review · Jun 2026

    Really appreciate Roger coming out to the house to not only treat for common insects that like to make their way into the house (regularly scheduled maintenance), but also exterminate a hornet nest we found on our deck this last week. Great service, arrives on schedule (and sends a text with arrival time when he’s on his way), and most importantly - no critters coming inside my house - or hornets potentially stinging us. Recommend Planet Friendly Pest Control to anyone looking for an exterminator.

  • Kathleen M.

    Google review · Jun 2026

    Great service. No bugs in the house! They quietly and quickly get the job done, no hastle.

  • San D.

    Google review · Jun 2026

    Roger was very kind and professional. He did an excellent job attending to areas of the exterior of our home that required extra attention.

  • Patti W.

    Google review · Jun 2026

    Gene Wright came highly recommended by multiple neighbors. He came out the same day I called and showed great knowledge about our mouse problem! Gene was responsible, knowledgeable and a delight to deal with. We highly recommend Planet Friendly Pest Control.

  • Denise A.

    Google review · Apr 2026

    This is my third year using Planet Friendly to control ants in my home. I have yet to see an ant. What a relief. This is a real necessity where I live. Thank you.

Dealing with pests around your home?

Hundreds of Google reviews across our verified service locations. Book a free initial inspection and we’ll start with the exterior — where most problems begin.

Get Your Free Inspection