My purple milkweed didn't return this spring either, and Im hoping it's just taking a year off. My Asclepias fascicularis was missing last year, but it returned this spring. Im going to carefully dig the spot where the purple was growing to see if the tubers are still there.

Back when I was a bit more adventurous about growing plants of highly borderline hardiness for this climate, I had a Cycas panzhihuaensis return from the dead two springs after it died back. Yes, it took more than a year off! Alas, the next winter was the first polar vortex winter, and little tiny single leaf Cycas wasn't going to survive that. It's a shame I wasn't cleverer back then about where to plant things - if I'd originally planted it on a south slope, it might still be around.

I have another cycad that might be fairly hardy, a Chumley hybrid, but I'm waiting for it to offset so I can try it outside and have a backup...so I might be waiting a long time. I think around here they will always be a long-term temp-perennial - probably true of Trachycarpus fortunei, too. Able to last 5-30 years before a bad enough winter takes them out. Which is fine in a way - you can enjoy them in the intervening years.

No...mine just die.

Thank you for your comments. Suzy you made me laugh. I have lots of plants that die too.

It makes me wonder if I have dug things up thinking they were dead when they were just napping.

I would have also put this in the native plants forum if we had one because I suspect some of those would make the list.

I've never grown orchids but those came up when I was reading about prolonged dormancy. I think it must be fairly common for them to sleep a few years and then reappear.

Worst than simply dying is actual murder. Only last week, I pulled out a heap of what I thought was the hatefully rampant lemon balm...even though they were growing in a suspiciously straight line. I missed one - which turned out to be salvia I had laboriously grown from seed...and then that awful realisation that I had tossed 18months of effort into the compost.

I have an awful feeling that at least a dozen gaura and a handful of baptisia have gone the same way (in manic weed pulling mode).

In my defence, I have terrible hay fever and cannot smell a thing, but I can't really claim that allergies have affected my brain (can I?)