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Penstemon duchesnensis

Duchesne Penstemon

Family PlantaginaceaeGenus Penstemon

Two vivid blue flowers seen face on, each throat pale and marked with a golden-orange beard, above gray felted leaves.
FlowerAndrey Zharkikh from Salt Lake City, USACC BY 2.0

About the plant

What it is and where it grows — not part of any germination protocol.

Habit
perennialPlants of the World Online
Flower
BlueRead from the photograph on this page

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Plants of the World Online — Royal Botanic Gardens, Kew; Read from the photograph on this page — Deno's Garden.

This source reports three treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1996

Difficulty High Rated by us, not by the source.

Start around February 15, 2027 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 Light: dark

    2/13 germinated in this phase.

Steps after step 1 run on after germination.

Germination happens during step 1, in 49 days.

23% germination in 49 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Penstemon p. 64Public domain
Show the original text
Penstemon (Scrophulariaceae). P. duchesnensis germ. 40(3/13 in 7th w)-70D(2/13 on 2nd d), 70L(1/14 in 12th w)-40(1/13), and none in 70D or OS.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Penstemon p. 64. 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, 1996

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

Start around December 15, 2026 for a May 3 last frost.

  1. Warm moist stratification

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

    1/14 germinated in this phase.

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 3 months from start to step 2. Germination happens during step 2; time not stated, 21 days assumed.

8% germination.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Penstemon p. 64Public domain
Show the original text
Penstemon (Scrophulariaceae). P. duchesnensis germ. 40(3/13 in 7th w)-70D(2/13 on 2nd d), 70L(1/14 in 12th w)-40(1/13), and none in 70D or OS.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Penstemon p. 64. 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, 1996

  1. Sow and cover

    Temperature: 70°F 21°C Light: dark

No stated waiting before sowing.

0% germination.

Nothing germinated at 70.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Penstemon p. 64Public domain
Show the original text
Penstemon (Scrophulariaceae). P. duchesnensis germ. 40(3/13 in 7th w)-70D(2/13 on 2nd d), 70L(1/14 in 12th w)-40(1/13), and none in 70D or OS.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Penstemon p. 64. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list.

How each step is done, in Deno’s words, and what Verified and Derived mean.

Germination trials

Readers’ own records of sowing this species, published after review. Share your trial · All trials

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