Deno’s Garden

Penstemon virens

Genus Penstemon

This source reports three treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around April 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on April 16, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    5 germinated in this phase.

Steps after step 2 run on after germination.

about 9 months from start to sowing. Then 84 days to germinate.

30% germination in 28–84 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. virens germ. best with seed DS 6 m at 70 in 40(30% in 4-12 w)-70(5% in 1-3 d). The DS is essential as seed DS 6 m at 40 germ. less as shown by 40(8% in 7-12 w)-70(1%) and fresh seed germ. none in 40-70 treatment. Germination failed with both DS seed and fresh seed when sown at 70. The above data were for seed collected in July. If the seed is allowed to remain on the dry stems all winter and collected in March, the effect is like DS and the seed germ. 40(11%)-70(17%).
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 Very high Rated by us, not by the source.

Start around April 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on April 16, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 40°F 4°C

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    1 germinated in this phase.

Steps after step 2 run on after germination.

about 9 months from start to sowing. Then 84 days to germinate.

8% germination in 49–84 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. virens germ. best with seed DS 6 m at 70 in 40(30% in 4-12 w)-70(5% in 1-3 d). The DS is essential as seed DS 6 m at 40 germ. less as shown by 40(8% in 7-12 w)-70(1%) and fresh seed germ. none in 40-70 treatment. Germination failed with both DS seed and fresh seed when sown at 70. The above data were for seed collected in July. If the seed is allowed to remain on the dry stems all winter and collected in March, the effect is like DS and the seed germ. 40(11%)-70(17%).
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 3

DerivedN. C. Deno, 1993

  1. Cold moist stratification

    Temperature: 40°F 4°C

No stated waiting before sowing.

0% germination.

Nothing germinated at 40.

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. virens germ. best with seed DS 6 m at 70 in 40(30% in 4-12 w)-70(5% in 1-3 d). The DS is essential as seed DS 6 m at 40 germ. less as shown by 40(8% in 7-12 w)-70(1%) and fresh seed germ. none in 40-70 treatment. Germination failed with both DS seed and fresh seed when sown at 70. The above data were for seed collected in July. If the seed is allowed to remain on the dry stems all winter and collected in March, the effect is like DS and the seed germ. 40(11%)-70(17%).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Penstemon p. 187. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list.