I don't know, I purchased mine as a small plant. I can say it has been fairly slow to bulk up - my little 2" pot from 2008 is still fairly small, perhaps 8" in diameter, and this spring will be the first I will be comfortable dividing it. There is good information on sowing these at horizonherbs.com (sorry, I don't know how to make this a link). I think my weather may be a bit iffy for it, though, perhaps too wet and warm. You may have better luck, being a bit colder than me.
