I can't say how it will do in your climate, but I tried this as a perennial to grow amongst Coast Redwoods in a semi-shaded irrigated garden here in Marin County, California, thinking it would be a nice woodland garden addition, and the plant just kind of petered out, with not much of a show of any kind. As an Alaskan native plant, it may need more winter chill than we typically get here, or it may have needed richer soil/more regular fertilizing to compete with the Redwood tree roots, or perhaps more sun. I bought this plant from www.anniesannuals.com, as I had seen it in bloom at the nursery, and as you say, the foliage and blooms are quite attractive. I'd think that dry soil would tend to limit its spread, so I wouldn't be too worried about this becoming a thug. As I said, it didn't do very well for me, but I only tried it the one time. Plenty of other plants I planted in the same circumstances did much better in competition with the Coast Redwoods, so it was a bit of an experiment. Hope someone else with more local experience also gives you some feedback.

I saw another Sanguisorba species from Japan growing well in the Univ. of California at Berkeley Botanic Garden yesterday, on a slope with dappled shade, and it did not appear overly vigorous or invasive, for what this is worth.

Menzies' burnet occurs in nature where Sitka burnet and great burnet meet, is thought to be a hybrid between them. These are wetland plants liking damp, sunny places in cool climates. I usually encounter them well up in the mountains, but they are not limited to the highlands.

i grow Sanguisorba minor regularly. seems to last a few years then peter out. but seeds pretty freely so i have never run out.

flowers aren't as nice as menziesii, but the leaves are great in salads- especially fruit salads. also nice to throw a twig in a glass of cheap red wine. its an old roman trick to make bad wine taste fresher.

Thanks for all the comments. Guess I'll give it a try and see how it works out. As eeldip notes, we can always throw a branch (woops, twig) in the wine to improve its flavor.