Hardiness: USDA Zone 3a: to -39.9 °C (-40 °F) USDA Zone 3b: to -37.2 °C (-35 °F) USDA Zone 4a: to -34.4 °C (-30 °F) USDA Zone 4b: to -31.6 °C (-25 °F) 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)
Sun Exposure: Light Shade
Danger: Seed is poisonous if ingested Handling plant may cause skin irritation or allergic reaction
Bloom Color: Pink Red Purple White/Near White
Bloom Time: Late Spring/Early Summer
Other details: Requires consistently moist soil; do not let dry out between waterings
Soil pH requirements: 5.6 to 6.0 (acidic) 6.1 to 6.5 (mildly acidic) 6.6 to 7.5 (neutral)
Patent Information: Non-patented
Propagation Methods: By dividing the rootball From seed; winter sow in vented containers, coldframe or unheated greenhouse From seed; sow indoors before last frost
Seed Collecting: Allow pods to dry on plant; break open to collect seeds
1) Sow @ 18-22*C [~64-71*F] for 2-4 wks; then move to -4 to 4*C [24-39*F] for 4-6 wks; then move to 5-12*C [41-53*F] for germination.
2) Sow at 4*C [~40*F] for 3 months, then place at 20*C [~70*F] for 3 months.
3) from the 2nd edition of Norman C. Deno's book, Seed Germination Theory and Practice -
-- Deno found that fresh seed germinated best at 70*F within 2 - 4 days (compare to Clothier in #1)
-- However, he found that seed dry-stored at 70*F germinated better when sowed first at 40*F for 3 months & then moved to 70*F for 3 months (compare to #2). Seed dry-stored for less than 6 months did worse than that stored at 6 month. Seed dry-stored at 70*F for 2 years was dead.
On Feb 11, 2005, DonnaMack from Elgin, IL (Zone 5a) wrote:
I put in 4 purchased primula japonica (pink and burgundy) in 1998. I have clay, highly alkaline soil, and at the time had few trees so the only shade available was on the north side of the house. If you compost them every spring and fall the results are spectacular. I allow some of them to go to seed and then sprinkle the seeds around. Without any further assistance they form little rosettes which are easily tranplanted, and in fact can be hacked in two and transplanted in spring. I now have at least 25, and they grow in excess of 1 1/2 feet tall. I water them perhaps once a week even during 90 degree temperatures in Zone 5A. Highly recommended. And try athyriam felix femina (lady fern) as a companion plant.
Has rosettes of light green, oblong, toothed leaves. Bears 1 or more whorls of salverform, deep reddish purple to white flowers sometimes with an eye.
Loves a constantly moist, fertile, neutral to acid soil in light shade, it will tolerate some sun if the soil never dries out.
Very easy plant to grow and looks great in a group.
This plant has been said to grow in the following regions:
Juneau, Alaska Gages Lake, Illinois Mount Prospect, Illinois Northfield, Illinois South China, Maine Littleton, Massachusetts St Paul, Minnesota Cayuga Heights, New York Hilton, New York Balfour, North Carolina Glouster, Ohio Molalla, Oregon Sherwood, Oregon Laflin, Pennsylvania