Hardiness: USDA Zone 5a: to -28.8 °C (-20 °F) USDA Zone 5b: to -26.1 °C (-15 °F) USDA Zone 6a: to -23.3 °C (-10 °F) USDA Zone 6b: to -20.5 °C (-5 °F) USDA Zone 7a: to -17.7 °C (0 °F) USDA Zone 7b: to -14.9 °C (5 °F) USDA Zone 8a: to -12.2 °C (10 °F) USDA Zone 8b: to -9.4 °C (15 °F) USDA Zone 9a: to -6.6 °C (20 °F) USDA Zone 9b: to -3.8 °C (25 °F)
On Mar 19, 2011, jrtinker from Palmer, AK (Zone 3b) wrote:
This lovely shade plant has proven hardier than expected. Best results for germination have come from sowing the seeds around the parent plant and letting them germinate when they want. Have also used GA-3 treatment successfully, and leaching/washing the seeds in a nylon sock suspended in a toilet tank for several weeks worked, too.
On Dec 30, 2010, dave12122 from East Haddam, CT wrote:
This is a hard plant to find in flowering size. If grown as a smaller plant, it can take 3-4 YEARS to flower. Mice find the roots attractive, so put rocks around the crown so they can't dig. Needs rich soil in at least partial shade. Lovely in bloom, but a little fragile when young and needs to be monitored closely.
On Aug 18, 2001, mystic from Ewing, KY (Zone 6a) wrote:
This perennial is a native of Japan. It grows up to 20 inches high and wide. It has attractive, bright green, paired leaves, which are divided into 7 to 11 irregularly toothed lobes, at the ends of erect stems. The large, cup-shaped,poppy-like flowers,are pale mauve. They are borne singly on thin stems in late spring.
This plant has been said to grow in the following regions:
Palmer, Alaska East Haddam, Connecticut Taylorsville, Kentucky Norway, Maine Shelburne, Massachusetts Glendale, Missouri Copake Lake, New York Ashley, Pennsylvania