If they are in the correct zone, it sounds like they need more water.
Other wise it could be cold damage. I have had them freeze to the ground in zone 8.

Mine get leaf damge like that from the cold every year. I have to cut them back in the spring. When I had it in a pot it got water logged and looked like that as well. Now that I have my house and its planted in a well drained spot it grew well last year even after I cut it back.

Thank you both. I had suspected the cold but needed to hear someone else say it. It is not exactly the appearance that you see from normal cold (freeze) damage on a plant.

It sounds like it might be Oleander Wilt Leaf Scorch, sometimes referred to as OWLS down here in South Texas.

Here is a website with information on Oleander Leaf Scorch which states the following:

Oleander Leaf Scorch

Oleander leaf scorch is so widespread here that oleanders are no longer recommended in Lakeway. The bacterium Xylella fastidiosa clogs water conducting vessels, causing scorched dry leaf tips and margins, yellowing, leaf drop and often death. Early aggressive pruning can sometimes catch the infection before it spreads, but more often than not the bacteria will move rapidly to the roots and then up through the rest of the plant. Bacterial scorch can resemble heat scorch, so you may want to have your plants tested before taking drastic action. The Texas A&M Plant Disease Diagnostic Lab will test for Xylella for a $50 fee (http://plantpathology.tamu.edu/extension/tpddl/tpddl.asp). For more information, read the document below by Skip Richter, Travis County Extension Horticulturist:

oleander_leaf_scorch_-_apr_05.pdf

Be sure to read the article by Skip Richter at Oleander Leaf Scorch for more information.

You might want to contact your County AgriLife Extension Service (formerly the Extension Office) for more information.

Thanks for the info. I no longer grow them, but it is nice to know.

I have only a couple of them left since I had problems growing them here on the coast. They were just too much work, and as they die, I don't replace them. They do smell so good though!

Mine only get leaf damage as do all the ones in my neighborhood. The stems are not affected and once warm weather gets here they turn all green again. I would wait and see what they look like when it warms up some. If it is this disease I would imagine they will look worse insead of better as it warms up.

During this past winter I noticed that many leaves on my 2 Oleander trees were turning yellow, curling and falling off. I hadn't trimmed them for a few years so I did a massive prunning in the spring. Leaves continued to yellow and each morning for about 2 weeks I would pick off the dying leaves.

All the internet sites lead me to believe that the problem was "leaf scorch" and recommended immediate removal.

I delayed removing them and now, 6 weeks since pruning, no more yellow leafs and the largest white and red flowers you have ever seen are sprouting everywhere on the plants.

If you love these plants don't give up too early.