I'm in the UK and Dinky Donna is somewhere in the middle of the spectrum for showing up. Always very reliable and grows well here.

Same goes for STGN, it shows up every season no problem.

Mine are all in pots if that makes any difference.

I also have the other two and they are also pretty consistent.

High Society is one of the earlier arrivals each year.

I hate to say it but you may have a problem unless you have had very cold temperatures up till now.

I would start digging down and checking for signs of life.

If there is any rot you may be able to deal with it before you loose the whole plant.

Let me know what transpires.

Good luck.

Dave

Hmmm. I see the stub of last year's plant but no new growth. Next time I go out, I will gently dig around that old stub for Dinky. One of my STGN has a pip, the other one doesn't. Ditto, I will gently dig around the center of that space, too.

Right now it's pouring cats and dogs, so I am not going outside to do anything!

Of those you mentioned I only have HighSociety and she’s an early pipper here

Almost everything is up or in pips here including High Society (although, it is just getting started). My Dinky Donna in a pot is not budging. Although, the crown is very firm. I think the one in the ground has started to unfurl, but I've been busy and not able to give it a lot of attention (yet).

OK, today I went out and dug around where Dinky Donna came up last year. I found the whole underground stem had turned to white mush. The same was true of my second STGN, in the same long planter as the STGN that is pipping. I have no idea why those two apparently had crown rot, as there are holes in the bottom of this planter. That means I need another Dinky Donna and maybe a second STGN. Darn!

Very sorry to hear your news.

Why does it happen?

It seems to be a random problem with no one easy answer, I certainly don't have one.

Get some replacements or try others and move on.

Enjoy the ones that survive, relish the choosing and purchasing of replacements.

At the end of the day it's a plant and life is too short to spend much time worrying about the cause of its demise.

Dave