You can't kill an Oleander - just start clipping. Keep in mind that every where you make a cut, TWO new branches will grow, so cut them back to the trunk to make a full shrub. It won't be long before the Oleander caterpillars defoliate it, that is to say, prune it for you!

Wear gloves and be very careful, they are extremely Toxic, the sap can penetrate your skin and cause severe nerve damage even death, never burn them even the smoke is toxic.

Here is a link that might be useful: Toxic Oleander

We have oleander hedges here and the texas chain saw massacre attacks them once a month. They never bloom because of that, but they're plenty healthy otherwise. They can stand a lot of abuse.

I like the. Looms but id like to keep
Them under control