Deno’s Garden

Penstemon humilis

Genus Penstemon

Protocol

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    30 germinated in this phase.

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 6 months from start to sowing. Then 3 days to germinate.

56% germination in 2–3 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Penstemon p. 187Public domain
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Penstemon (Scrophulariaceae). Four types of germination were observed. Most Rocky Mountain species of a perennial nature germ. largely at 40 and often sowing at 70 was fatal or near fatal. A second group are short lived species that can flower the first year from seed typified by P. humilis germ. best in 40(30% in 8-12 w)-70(56% in 2-3 d). Sowing seed at 70 is fatal. This was confirmed with two other samples.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Penstemon p. 187. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.