Any tips on how to legally and safely get rid of this for good? I have been fighting this plant since circa 1985. It laughs at Roundup and all other herbicides; at best they burn off the new shoots. It likes to grow up against the super six fence and gets under the fence and in the sheet joints breaking the fence. It also grows up against the trunks of other shrubs and tree killing them by blocking out the sun (and making the use of chemical herbicides more difficult). Yes; the honeyeaters love nesting in it and feeding on the flowers but they also spread the seeds in their poop so it is popping up in adjoining blocks along fence lines well away from my infestation. I've also see it in bushland in the area; I hope my "Audrey II" (per the people eating plant in Little Shop of Horrors) wasn't the source. I thought I had beaten her about 20 years ago when I had the kids pet rabbits fenced in around her and they ate all the new shoots that popped up. But when the rabbits left "Audrey II" returned with vengence. Goats and/or Pigs would probably work but the RSPCA, neighbours and Council would doubtless frown on this. Despite the noisy protests of the honeyeaters, I keep lopping it and clipping off or killing all the new shoots with herbicides. But she persists and as soon as I show any vulnerability (e.g. temporarily away or incapacitated by illness) and neglect my lopping and trimming she resumes control of the garden. My tip is don't ever plant one in Perth metro. I am suprised it's not a declared noxious weed. If the WWII nuclear war happens I am sure it will survive along with the roaches. It's even a pest in it's native USA see: http://forums.gardenweb.com/discussions/2203179/how-to-get-rid-of-trumpet-vine
The problem with digging the roots out is that in this part of Bibra Lake (well at least on my block) there is a solid limestone layer under the top soil varying between a few inches and a foot intermingled with limestone boulders. I guess these vines also like limestone. On the postive side I guess the roots of the vine appear to be slowly splitting and breaking limestone layer into smaller pieces so future generations may see a benefit.
Perhaps I should try the vinegar as suggested here http://davesgarden.com/guides/pf/go/644/ but will it kill all my other adjacent plants? It also mentions something called Vine-X being successful. Though not available in Australia, its constituants are listed here https://www.landsteward.org/page.cfm/10239 so I might be able to find a similar product.
I'll try this https://www.bunnings.com.au/yates-250ml-tree-and-blackberry-weed-killer_p3010221 albeit very reluctantly as it seems almost as noxious as the vine.