My huge green Cordyline fruticosa should have died this summer. I got fed up with it last winter -- no matter how far from all the other plants, no matter how careful I am to wash down the leaves when watering, no matter how cool and moist the environment, it still always gets spider mites, every winter, and I've gotten sick of dealing with them. So this spring, I put it outside.
The goal wasn't necessarily to kill it. I just wanted to get it away from the other plants, so the mites wouldn't spread. It had spent a summer outside before, so I figured it could handle it. On the other hand, there was something a little passive-aggressive about my method: I didn't try to gradually acclimate it to the new conditions. I just shoved it out there and let it fend for itself. Then I "forgot" to water it, even though we weren't getting very much rain. It responded the way you'd expect: first it sunburned, then it (partly) defoliated, and by mid-August I was ready to throw it out.
So we moved it to the back yard (there's a pile where we're dumping plant-related waste, soil, lawn clippings, etc. It's not quite a compost pile, because we're not trying to manage it like a compost pile, but we do expect it to break down into soil eventually.), but then for whatever reason it didn't get dumped. And since it was closer to the garden hose, it got watered when I thought of it.
And then the damn plant started to grow new shoots from its base. Apparently it had been living off the stored water and starch in the swollen rhizome at its base all summer because I wasn't watering it properly. Then we got some rain besides, so suddenly it's ready to grow again.
And I guess it'll get the chance. I get frustrated with C. fruticosa because of the spider mites (I gave up on the other Cordylines at the end of June), but I really like it otherwise, and if it's just the one plant, and it's growing lots of new stems at once . . . well, I'm not made of stone. I've cut back the old stems, and the Cordyline can stay for another year, as long as it behaves itself. No doubt I'll regret this decision next February, but it's not like I have to kill it now or I forever lose the chance, right?