What it is and where it grows — not part of any germination protocol.
The plant
Habit
Deciduous shrubPlant Finder
Height
3-5 ftPlant Finder
Spread
3-4 ftPlant Finder
Flower
Showy; pink to white with purple basal petal patchesPlant Finder
Blooms
April to MayPlant Finder
Native range
China SoutheastGBIF Backbone Taxonomy
Native range
China, Tibet, BhutanPlant Finder
Hardiness zones
4-8Plant Finder
Note
Nicking the seed, reported to help in the first edition, did not hold up. GA-3 gave only a small gain.Seed Germination Theory and Practice, 2nd ed.
Note
Relatively pest free. Some canker, leaf blight, stem wilt and scale.Plant Finder
Growing conditions
Sun
Full sun to part shade
Soil
Deep, fertile, medium moisture, well-drained
Watering
Medium
Toxicity is noted only where a source states it. No note here is not a finding of safety.
Sources: Plant Finder — Missouri Botanical Garden; GBIF Backbone Taxonomy — Global Biodiversity Information Facility; Seed Germination Theory and Practice, 2nd ed. — N. C. Deno.
This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1993
Difficulty ModerateRated by us, not by the source.
Start around March 21, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 20, 2026.
1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
14% here.
3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
A further 16%.
4
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
35% -- the largest flush.
5
Cold moist stratification
Temperature: 40°F 4°C
A last 11%.
about 12 months from start to sowing. Germination time not stated; 21 days assumed.
35% germination.
14, 16, 35 and 11 per cent over four cycles -- about three quarters of the seed in all.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1993
Difficulty ModerateRated by us, not by the source.
Start around January 2, 2027 for a May 3 last frost.
1
Warm moist stratification
Temperature: 70°F 21°C
25% here, in the fourth month. The radicle and its branching root system form here. This is what Deno counts as germination.
2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
A further 5%.
3
Warm moist stratification
Temperature: 70°F 21°C
30% on the third day. The single true leaf forms only now. Germination is hypogeal.
about 3 months from start to sowing. Then 3 days to germinate.
30% germination in 3 days.
25% in the fourth month, 5% in the cold, then 30% on the third day back at 70.