Incarvillea diffusa
Family BignoniaceaeGenus Incarvillea
Also published as Incarvillea arguta. You are in the right place.
This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around March 27, 2027 for a May 3 last frost.
- 1
Sow and cover
Temperature: 70°F 21°C · Light: either
No stated waiting before sowing. Then 9 days to germinate.
100% germination in 6–9 days.
Light made no difference: 100% either way.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around March 30, 2027 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
- 2
Warm moist stratification
Temperature: 70°F 21°C
92% germinated after the move, in 2-6 days.
No stated waiting before sowing. Then 6 days to germinate.
92% germination in 2–6 days.
Faster after the move, but it gives up eight percent to do it.
This source doesn't state how long.