Lagopsis marrubiastrum

I look forward to hearing more about this plant too, one that I started from seed this year as well.  (I've already planted mine out in the tufa garden, where they will either live or die... unless some different and compelling advice comes along that causes me to move them ;)  ...)  The plants have adapted well to outdoor conditions, tightening up nicely:

Much more significantly, Stephanie F. is growing it here in Calgary, so presumably it has proved hardy, and is growable... at least by the experts.  :)  (If I recall correctly from the visit to Stephanie's when Todd took the following photo, this plant would have been in the front crevice garden.)  It would be great to hear firsthand how it's done!
http://nargs.org/nargswiki/tiki-browse_image.php?imageId=3734

This site suggests rock crevices with a "favourable water regime" (whatever that might mean):
http://www.kadel.cz/flora/g/kvCard.asp-Id=10713.htm

Here's a bit of description of its native habitat:
http://greif.uni-greifswald.de/floragreif/?flora_search=taxon&taxon_id=380
Another habitat description:
http://pisum.bionet.nsc.ru/kosterin/plants/lamiaceae/lagopsis.htm

This is clearly not a 'popular' plant, but I will report on my experience over the past year nonetheless. I successfully germinated 12 seedlings, and 8 got potted up and 4 went to our Chapter plant sale. I put 5 of the 8 into the open garden, and at least one has survived the winter, and is now showing green and growth. One other may be alive, but the rest are gone. They simply disappeared. Interestingly, the one that is doing the best is in a richer soil, with a bit of afternoon shade, sheltered on the west from late afternoon sun. I'll let you know how things progress, and whether the plant is worth growing. It looks good in photographs, and hopefully I'll get some flowering to compare.

Thanks for the update, Peter.  I'll add to it with my findings....  From my photos, it looks like I germinated 4 seedlings last year, and planted out one in the end.  It has survived the winter, and has leafed out, planted in tufa in full sun.  They appear to be quite herbaceous - here it is on April 28th and again on May 11:
 

I grew a couple more from seed this year, so will have them to observe as well.

A couple of tiny flowers starting to peek out of a ball of fur on last year's Lagopsis marrubiastrum seedling...