Some agastachse overwinter here and others are simply not hardy enough probably including some that are sold at nurseries as hardy. I have luck with the blue ones.

I'm sorry, I should have clarified. I know the more annual anise hyssops, or the ones hardy to zone 7, that require drier conditions will not overwinter. My failures were with the standard blue herb, Agastache foeniculum. It's supposed to be carefree, and I can't get it to come back! I'm like you peren.all. I have no idea why the blue version won't overwinter for me. There is NOTHING online about them being short-lived, etc.

I planted at least 10 Agastache foeniculum plugs I started from seed last year. All the ones in leaner, more sandy soil came back and look great. The one in richer heavier soil that has more clay and a thick wood mulch is gone, even though that soil still drains pretty well. Maybe it needs faster drainage or a lighter mulch layer for better air exchange?

Same as asarum... I only have luck with the blue ones also.

Skip I agree with the lighter mulch. Ask me how I know : /

OK, I have to take back the part about it being described as short-lived. There ARE informational websites that say that. But it shouldn't be THAT short-lived! I have plenty of crappy soil, will experiment with it there. ;-)

I've grown agastache for years, both in CO and north of Boston. It is a mediterranean plant that must have extremely fast draining, sandy, gravely soil. In CO, it did OK in an amended clay but because CO is relatively dry, sunny year round and has less snowfall then MA they were always hardy. When I planted them in MA I did amend well the first time....or so I thought. Lost 2 out of 3 during winter. Next spring when I planted I pretty much replaced all the soil for each planting hole with a mix of sand, gravel, bit of compost and native soil. Made sure I planted in the sunniest spot I had....even in winter. They all then took off and survived the winters. They demand a lean, alkaline soil, not acid. Root rot is normally what takes them down during winter.

The variety Golden Jubilee which is a vibrant lime green seems much more forgiving of NE soil conditions and gently seeded here and there....good for giveaways.

Realize that although you're doing your best to emulate the Mediterranean, Agastache is never going to be as happy in NE as it is in dry, sunny Western climates.

I thought mine didn't come back, but I see it--only a few inches tall at a time when the peonies are about the bloom....so maybe they are just late to emerge in the Spring?

Good information, jama. Violet, I'll keep my eyes open!