How to Cure Oleander Leaf Scorch

Oleander blossoms add summertime color to a garden.

Oleander plants flower throughout the summer, producing pink, red, peach, yellow and white blossoms. They thrive in regions with mild winters, moderately warm summers and heavy rainfall. In particularly humid climates or coastal regions, bacteria called Xylella fastidiosa is known to cause leaf scorch. Leaf scorch occurs when the bacteria feed on the oleander plant's xylem, the tissues responsible for transporting water throughout the leaves. You may not be able to completely cure leaf scorch, but you can try to control it.

Things You'll Need

• Watering can
• Garden hose
• Tetracycline
• Pruning shears

Instructions

1. Check your soil moisture levels to more adequately diagnose the leaf problem. Oleander plants require generous watering; you should be able to stick your finger into the soil and have it come out slightly wet. The University of California at Davis explains that leaf scorch symptoms are similar to those of drought. If your leaves are wilted and yellow but your soil is moist to the touch, bacterial infection is a likely cause. If the soil is dry, increase daily watering and see if the plant perks up.

2. Spray the plant with tetracycline or a similar antibiotic. Tetracycline does not cure oleander leaf scorch, but it will slow its spread temporarily as you manage the infestation.

3. Prune the plant heavily. Cutting back large portions of the infected oleander can help remove the bacterial infection if you spot the leaf yellowing symptoms early enough. The University of Arizona warns that a heavy infestation cannot be controlled, as the bacterial will have spread throughout the oleander via xylem canals.

4. Dig around the oleander plant and expose the root structure. Oleander roots typically extend just one foot into the soil.

5. Remove the entire plant, including the exposed roots. In many cases, heavy pruning will not help prolong the plant's life. Pruning should be considered a temporary management measure. When the disease recurs, removing the oleander plant prevents spreading leaf scorch to other nearby plants.

References

• "Simon and Schuster's Complete Guide to Plants & Flowers"; Frances Perry; 1976
• University of California, Davis: Oleander Leaf Scorch
• University of Arizona Extension: Plant Pathology