I had success with a pencil-sized sprig with hair-like roots from a 100 + year old plant. BABY it! Water well with 1/8 strength of fertilizer every couple days all season for two years. Protect it from being disturbed for a few years so it can get established. Watch for urinating dogs, harsh winds, deer, heavy snow, ect.... Mine took 4 years to bloom, but every year it grew substaincially. Well worth the wait. Good luck-you can do it.