My guess is you will very carefully have to apply a glycophospate product (RoundUp) that says it is "brush killer". Don't do it on a windy day and be very careful to shield anything you don't want killed.

I'd start with Tally's suggestion.

If it's allowed in your area, and you have the time to watch it AND it's not too close to the house, you could dump a bag of charcoal in the hole and try burning the stumps out.

If you can get enough of the roots cut, you can try pulling them out with a truck, but I don't know if you want to put in the time and effort to excavate that far.

The organic method that I've seen says to dump a bunch of sugar (they suggest any jams or jellies or other items that are lurking in the back of the fridge/pantry and shouldn't be eaten) on the stump, cover with mulch, and keep moist. I'm not sure I'd want to do that right next to the house.

I managed to kill the roots of a crepe myrtle by dumping the water from scrubbing the cats' litter boxes with bleach and soap on the area. It took quite a while for anything else to start growing there, though!

If you can keep water away from the roots, that might help them die.

I think I finally killed my cedar elm (it kept sending up shoots even though it had been chopped down and my father tried burning it out) by putting the roundup brush killer on the leaves, so if you get the bushes weak enough, that could be the last straw.

I wish you luck with your war of attrition!

They have some stuff they sell at co op farm stores that will even kill cedar and mesquite. I don't know the name of it but its heavy duty stuff. You can ask a store like that about it.

???? I don't think you can.

They're practically immortal where I live, which is Phoenix, Arizona. And in the case of having to remove my dad's 40 year old oleander stump it was a 'perfect storm.' When dad had planted it, we had sheep and to protect the oleander from our ram he put sheep fencing around it. Of course, 40 well fed and watered years later, it's a dirty monster. One that does not biodegrade into any thing compostable, the smoke it toxic, as are all parts of the plant and since this one had been planted up against a shared fence and close to an underground irrigation pipe that supplied the neighborhood...I was in for a long term project...and by long I mean years. We cut it back with lopers, the fence was totally incorporated into a multi-trunk mess of all diameters. Turned off the water to it, that didn't matter. Poisoned it. Didn't matter, it grew back year after year. Until finally I dug down and exposed as many roots as possible, cut it back and into as many pieces as possible with a sawzall and then a chainsaw. Let it dry out as much as possible. Cut at it and I mean slashed it. Added Kingsford or your generic charcoal briquettes. lighter fluid, MAKE IT HOT, GLOWING HOT. I made sure there's not danger or embers blowing and did this on and off for a couple weeks. It's been about four years since we started and it comes back every time. There were 3 of them in a row. The smallest one, the easiest to kill, after almost a decade...fresh, green oleander shoots started growing out of the dead stump. So, I know this one will be back. If you leave any of it behind, its like bremuda grass, it will spawn new growth in time. Be positive though, you might be dead by then and someone else will have to deal with it... ;)

I have not had to remove a large oleander, but I can say that the method Tally is talking about has worked for me in removing bamboo, a very large burford holly, wax leaf ligustrums and gingers that simply will not die. Plants with thick and/or glossy leaves respond poorly to herbicides, so I wouldn't bother with that method. Cut it to the ground and as soon as new foliage emerges, cut the foliage. Do this over and over, NEVER allowing any foliage to grow and the plant will die. They need the foliage for photosynthesis. When the new foliage becomes weaker and less vigorous, you can apply your herbicide as the young, tender leaves are more vulnerable to the round up and that may quicken the process.

Molly

It was going to take too long for these dwarf red oleanders to recover. I hope there are many years ahead of me, but I just couldn't see wasting even a year when there are so many pretties to plant in this prime real estate.

I had a large oleander in the back yard I wanted gone. Cutting it down was useless, it grew right back, and it was too large to pull out. So I cut it down and let it get around 2-3 feet tall so it would have foliage. I sprayed regular Roundup generously all over the foliage every other day for about 14 days and it was dead and has not returned at all.

The discussions I read here recently about how hard they were to remove is what prompted me to action. I was unhappy with their sluggish performance so Why add the Herculean chore to remove if left to its own devices. I removed one and DH did the other as beyond my capabilities. Good riddance!

I went at it with a jackhammer an axe and a sawzall. That first hammer bit got stuck in the tough roots. Eventually, removed the bit, and put on a chisel bit. That helped. Back to the spade bit to clean deeper. Also used a sawzall and went after the roots just under the surface. Sawzall worth having or a chainsaw (never thought of that) Jeeze never fought a plant in my life like an oleander.

I went at it with a jackhammer an axe and a sawzall. That first hammer bit got stuck in the tough roots. Eventually, removed the bit, and put on a chisel bit. That helped. Back to the spade bit to clean deeper. Also used a sawzall and went after the roots just under the surface. Sawzall worth having or a chainsaw (never thought of that) Jeeze never fought a plant in my life like an oleander. My neighbor is spending $2,000 to have 2 big ones removed.