How to Troubleshoot a Live Oak Tree
- 1). Examine your live oak's leaves closely for clues to its condition. If the leaves are turning brown along the margins and curling up--but not wilting--your live oak tree may have oak anthracnose, a fungal disease that develops during wet weather. It is usually not fatal to the tree, and you can treat it with a commercial fungicide. Rake up and destroy all fallen leaves, and prune out any diseased branches.
- 2). Examine leaves for the small, round, tan-centered spots that could indicate Septoria leaf spot. Rake and destroy fallen leaves, and spray with a chemical fungicide.
- 3). Look for yellow-veined leaves that are falling off, turning bronze, wilting, or exhibiting browning at tips and margins--all signs of oak wilt, an aggressive disease that is spread by oak bark beetles. If it is summertime, this makes a diagnosis of oak wilt more likely. The disease is incurable, and can kill a tree within a few months; affected trees must be removed and destroyed.
- 4). Look for a white, powdery dusting on leaves, a sign of powdery mildew. Leaves may also be misshapen, stunted and falling off. Treat with a commercial fungicide.
- 5). Examine the bark on the trunk and branches for twig canker--another fungal disease which affects live oaks--and which causes small, sunken cankers that look like grooves in the bark. Although this disease can cause some twigs and branches to die, it is usually not serious.
- 6). Look for the presence of small green worms, grayish or brownish moths, cocoons, and silky threads hanging from branches--all signs of oak leaf rollers and oak canker worms. Although they can chew some of the leaves to lace, these insects generally don't do enough damage to pose a threat to your live oak's survival. According to Texas A&M, you can treat these pests with Bacillus thuringiensis, a non-toxic bacterial insecticide.
- 7). Look for leaves turning yellow, or chlorotic, which may indicate an iron deficiency. If so, you can correct the condition by spraying the leaves with a solution made by mixing iron sulfate at a ratio of 3 oz. per gallon of water.
- 8). Consult your county extension office or a reputable nursery for more guidance if you are unable to identify the problem yourself--or if you want your diagnosis confirmed.
