I've cut mine down to the bare trunk trying to kill them and they just keep coming back and for every branch I cut off,
it gets replaced by several. I would say oleanders are very hardy and very hard to kill.

Thanks....I've gone around the neighborhood and it appears the wind and the excessive heat and then cold probably has something to do with excessive drooping and yellow leaves as the ones I see look like mine. I cut the flowers off the branches that were being weighed down and they seem to perk up... I just want them "tall" to block my windows from the street :-)