Question

Deceased Oleander   QUESTION: Dear Kathy,

We have an area of Oleanders that have died, but the others in the same area seem to be doing fine. The leafs turned yellow then brown and then the stems died. What could this be.

Thanks,

Troy Smith

ANSWER: Hi Troy,  You do not say where you live which makes it harder to figure out what is going on.  This is what it may be.  Oleander leaf scorch is a disease found mainly in southern California. It is caused by the bacterium Xylella fastidiosa, which is the same species (although a different strain) that causes Pierce's disease of grapevines and almond leaf scorch. The strain of X. fastidiosa that causes oleander leaf scorch will not cause Pierce's disease, so removing oleanders will not reduce the source of X. fastidiosa that can affect grapes. As with other diseases caused by X. fastidiosa, the bacterium is vectored by insects, primarily sharpshooters, which feed on the water-conducting tissue (xylem) of the plant.

This disease was first noticed on oleanders in the Palm Springs-Indio area of Riverside County and in Tustin (Orange County) in the early 1990s and has spread to other parts of southern California including Santa Barbara, Ventura, San Diego, San Bernardino, and Los Angeles counties. Evidence to date suggests that the disease resulted from the introduction of a strain of X. fastidiosa new to California. The disease has now been reported across the southern United States. While the disease has not yet been recorded north of Santa Barbara County, it is believed that it could spread north through California's Central Valley and along the coast where the glassy-winged sharpshooter is established. Oleanders affected by this disease decline and then die, usually within 3 to 5 years of the first symptoms. There is no known cure.

The other thing it could be is not enough water which has the same symptoms.  So only you would know.  kathy

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QUESTION: Sorry Kathy,

This is in Houston, Tx if that helps. We do have good water on these plants as all of the other plants on both sides of the dead ones are fine.

Thanks,

Troy

Answer
Hi Troy, the above maybe the problem with your plants as it has moved into Texas by the glassy winged sharp shooter.  
The diagnostic symptoms on oleandersinfected with Xylella fastidiosa are browntips and margins of leaves.OleanderLeaves on one branch will turn yellow anddroop. This is quickly followed byscorching of the tips or margins of theleaves. As one branch develops symptomsand dies other branches start showingsymptoms. Often the first symptomobserved is the tips of the leaves turningbrown. Control There are no practical controls for diseasescaused by Xylella fastidiosa and there are noregistered pesticides which control Xylelladiseases. Controlling the vector andremoving infected plants has not been effective at preventing the spread of Xylella to healthygrapes or oleanders. Experimental treatments with antibiotics have inhibited symptomdevelopment but are not commercially feasible. Infected oleanders usually die within 3 to 5years after initial symptoms are observed or sooner.  Check this out with some photos of the leaf and see if it looks the same.  kathy