Deno’s Garden

Penstemon mensarum

Genus Penstemon

This source reports 7 treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1998

Difficulty Low Rated by us, not by the source.

Start around March 22, 2027 for a May 3 last frost.

  1. Gibberellic acid soak

  2. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 14 days to germinate.

100% germination in 14 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain
Show the original text
Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. 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, 1998

Difficulty Low Rated by us, not by the source.

  1. Sow outdoors and leave it

    Up in March.

No stated waiting before sowing.

100% germination.

This source doesn't state how long.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain
Show the original text
Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. 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, 1998

Difficulty Moderate Rated by us, not by the source.

Start around February 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on February 22, 2026.

  1. Dry storage

    Duration: 365 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Temperature: 40°F 4°C

about 12 months from start to sowing. Then 42 days to germinate.

44% germination in 42 days.

This source doesn't state how long.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain
Show the original text
Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. 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 4

DerivedN. C. Deno, 1998

Difficulty Moderate Rated by us, not by the source.

Start around November 25, 2026 for a May 3 last frost. Too late for spring 2027 — that needed starting on November 24, 2024.

  1. Dry storage

    Duration: 730 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 Light: dark

    1/9 germinated in this phase.

Steps after step 2 run on after germination.

about 2 years from start to sowing. Then 42 days to germinate.

44% germination in 42 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain
Show the original text
Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. 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 5

DerivedN. C. Deno, 1998

Difficulty High Rated by us, not by the source.

Start around February 1, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Temperature: 40°F 4°C

No stated waiting before sowing. Then 63 days to germinate.

14% germination in 63 days.

This source doesn't state how long.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain
Show the original text
Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. 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 6

DerivedN. C. Deno, 1998

Difficulty Very high Rated by us, not by the source.

Start around June 19, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 18, 2026.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: light

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: light

about 9 months from start to sowing. Germination time not stated; 21 days assumed.

7% germination.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain
Show the original text
Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. 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 7

DerivedN. C. Deno, 1998

Difficulty Very high Rated by us, not by the source.

Start around March 7, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 6, 2026.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: dark

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: dark

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 12 months from start to sowing. Then 35 days to germinate.

6% germination in 35 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Penstemon p. 52Public domain
Show the original text
Penstemon (Scrophulariaceae). Some of the following data are updates on species reported in the 1st Suppl. As noted in the 2nd Ed. and 1st Suppl., 'there is a wide range of germination behaviors in this genus ranging from requirements for light, oscillating temperatures, low temperatures, and GA-3. P. mensarum germ. 70 GA-3(100% in 2nd w), 40(2/14 in 9th w), OT(100% in March), 70L-40-70L(1/15) and 70D-40-70D-40(1/16 in 5th w). Seeds DS 1 y germ. 40(4/9 in 6th w). Seeds DS 2 y germ 40(4/9 in 6th w)-70D(1/9 on 5th d).
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Penstemon p. 52. 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.