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Penstemon acuminatus

Sharpleaf Penstemon · Sand Dune Penstemon · Sand-dune Beardtongue

Family PlantaginaceaeGenus Penstemon

Tall spikes crowded with lilac-purple tubular flowers, rising from stems clasped by broad blue-gray leaves, at the edge of a sandy track.
The whole plantSheri Hagwood, Bureau of Land Management.Public domain

About the plant

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

The plant

Habit
perennialPlants of the World Online
Habit
Perennial, Forb/herbPLANTS Database
Height
2.0 ft60 cmPLANTS Database
Flower
BluePLANTS Database
Blooms
Late SpringPLANTS Database
Native range
Native to the lower 48 statesPLANTS Database

Growing conditions

Sun
Shade tolerance: HighPLANTS Database
Soil
Adapted to coarse textured soilsPLANTS Database
Soil pH
6.0-8.0PLANTS Database
Moisture
Moisture use: LowPLANTS Database
Watering
Drought tolerance: HighPLANTS Database

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; PLANTS Database — USDA NRCS.

This source reports two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around January 11, 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

    5 germinated in this phase.

Steps after step 1 run on after germination.

Germination happens during step 1, in 84 days.

54% 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. acuminatus germ. 40(54% in 4-12 w)-70(5%) and 70-40-70(10%).
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 High Rated by us, not by the source.

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

  1. Warm moist stratification

    Duration: 90 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

about 6 months from start to step 3. Germination happens during step 3; time not stated, 21 days assumed.

10% germination.

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. acuminatus germ. 40(54% in 4-12 w)-70(5%) and 70-40-70(10%).
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.

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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