blue/purple Agastache cultivar questions
So I'm working on this project for work. It involves introducing some new plants to our landscape architects.
One of the plants I'm featuring is going to be Agastache, specifically the foeniculum and rugosa hybrids. I've only had experience with 'Golden Jubilee' and some of the western forms of hyssop (which don't work well here).
I was hoping you guys could share your findings on other foeniculum/rugosa varieties? I'm especially interested on knowing:
1) do they reseed or are they sterile?
2) are they fairly long-lived? How long?
3) have they been reliably hardy in zone 5?
I'm going to highlight the new cultivar 'Blue Boa', since it is gorgeous and also seems to be sterile (a GW buddy mentioned this to me, as well as someone who trials plants at CO university). Anyone else grow and like it?