Are these the larger blue flower variety, or the small white ones? The latter (small white) grow like weeds. I had soil added to my garden 4 years ago, that had bits of the roots of these in it. Still today, I find the thing sprouting up, choking out other plants. The larger blue flower variety I have had success with cuttings -- about half of them survived.
at 6:03 PM on Sep. 16, 2010