I have never seen a hill of aeoniums planted like that. I wish more people would plant like that  it is a great fire break & landslide prevention idea. It looks like the aeoniums & echiums at the top of are flowering  it must look great when in full bloom. That hill must re-seed like crazy. That is a beautiful picture of the bay.

I've seen clumps of it blooming along the bluff in Magnolia but not for a while now :-) I tried it 3 years in a row and even got the things to overwinter a couple of times before a late spring frost cut them back. Based on my limited but futile attempts, I'd say unless you have a large greenhouse, chances are not good for success. It takes two seasons before it blooms and really would like as close to a frost-free winter as possible, so overwintering them in a protected location is pretty necessary. Or at least it has been for the past few winters :-) And even grown in a container (as mine were), this rapidly becomes a BIG plant, so a large protected space - like a greenhouse - is best.

I'm in Adelaide and I have the same thing on my echium. I had it last year as well. It rots the tips of the stems and they just break off easily, and the maggots are inside. I have tried Confidor and Pest Oil but as I only did it today I'll have to wait and see if either of them works. I couldn't find anyone who'd heard of it, and this is the first mention I've seen of it on the net, so I'd be really interested if anyone knows what it is and how to treat it!

Official State noxious weed listings are seldom comprehensive. What matters is that U.C. Davis is calling it a weed. And that other sources show it to be a widespread pest - it is just a matter of time before additional States start listing it. And what happens if you suddenly aren't able to deadhead your known western weeds collection? You've made arrangements for somebody else to come in and curb or eliminate them? All it takes is for your control measures to stop - or be defeated somehow - and then they can start spreading out from this foothold you have established - and are maintaining. This is why such plants are referred to as "garden escapes" or "escaped ornamentals" - they left the confines of cultivation and became problematic.