Deno’s Garden

Penstemon nitidus

Genus Penstemon

This source reports two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Low Rated by us, not by the source.

Start around February 8, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Temperature: 40°F 4°C

No stated waiting before sowing. Then 56 days to germinate.

95% germination in 21–56 days.

This source doesn't state how long.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Penstemon p. 187Public domain
Show the original text
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. nitidus germ. best with seed DS 6 m at 40 in 40(95% in 3-8 w) and less with fresh seed in 40(74% in 5-12 w)-70(3% in 2-3 d). Seeds sown at 70 and seeds DS for 6 m at 70 were dead.
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.

Protocol 2

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around October 13, 2026 for a May 3 last frost.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    3 germinated in this phase.

Steps after step 1 run on after germination.

about 3 months from start to sowing. Then 84 days to germinate.

74% germination in 35–84 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Penstemon p. 187Public domain
Show the original text
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. nitidus germ. best with seed DS 6 m at 40 in 40(95% in 3-8 w) and less with fresh seed in 40(74% in 5-12 w)-70(3% in 2-3 d). Seeds sown at 70 and seeds DS for 6 m at 70 were dead.
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.