Anise Hyssop is a short-lived perennial. Here in the fierce heat of the subtropics, I've never succeeded in getting it to survive more than one year. It's supposed to self-seed, but it has never done that for me, either. In any event, the seeds are slow to germinate, even with a soil temp of around 20C. I don't know where Portland is, or what the climate is like there, but it would seem that if it's going to resurrect, it still needs a bit more warmth. When the books say 'it will come back in spring', you need to remember that spring lasts for about 3 months - it could well be that it comes back when it's nearly summer!

I'm in NJ so it is a lot colder here than Portland, but I noticed my anise hyssop has just started poking up some tiny new green leaves from the ground this week. It was quite warm the past week too - in the upper 60's, even low 70's, all week (rather warm for march in this area). Meanwhile, some of my other herbs and veggies (like thyme, sage, chives, hollyhock and chard) were already growing a couple weeks ago.

This is it's first spring (I just planted mine last summer too) so that's all I can say since I'm new at growing this plant. Good luck, hopefully yours will start growing soon too!

Hi I live in Indiana, I grew Anise Hyssop from seed last year several plants, they all seeded for me too, I cut them back in the fall and they are reappearing just now, so if your climate is colder i would imagine you may see it pop up soon