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Phacelia grandiflora

Large-flowered Phacelia · Largeflower Phacelia

Family BoraginaceaeGenus Phacelia

Pale blue flowers veined in violet with yellow-green throats, their dark stamens arching out over bare soil.
FlowerUnknown authorUnknown authorPublic domain

About the plant

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

Habit
annualPlants of the World Online
Habit
Annual, Forb/herbPLANTS Database
Flower
Lavender-blueRead from the photograph on this page
Native range
California, Mexico NorthwestGBIF Backbone Taxonomy

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; Read from the photograph on this page — Deno's Garden; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

  • Largeflower phacelia grows in the coastal hills and southern Transverse Ranges of southern California and Baja California, including in areas recently burned by wildfire. Wikipedia: Phacelia grandiflora

This source reports 4 treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Low Rated by us, not by the source.

Start around March 15, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Temperature: 40°F 4°C Light: either

Germination happens during step 1; time not stated, 21 days assumed.

90% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Phacelia p. 191Public domain
Show the original text
Phacelia (Hydrophyllaceae). P. grandiflora germ. 70(80% in 3-4 d) and 40(90% in 3rd. w). Light had no effect. Seed DS 6 m at 70 germ; less, 70(2%) and 40(5%).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Phacelia p. 191. 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 Low Rated by us, not by the source.

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

  1. Sow and cover

    Temperature: 70°F 21°C Light: either

No stated waiting before sowing. Then 4 days to germinate.

80% germination in 3–4 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Phacelia p. 191Public domain
Show the original text
Phacelia (Hydrophyllaceae). P. grandiflora germ. 70(80% in 3-4 d) and 40(90% in 3rd. w). Light had no effect. Seed DS 6 m at 70 germ; less, 70(2%) and 40(5%).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Phacelia p. 191. 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

Difficulty Very 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. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Temperature: 40°F 4°C Light: either

about 6 months from start to step 2. Germination happens during step 2; time not stated, 21 days assumed.

5% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Phacelia p. 191Public domain
Show the original text
Phacelia (Hydrophyllaceae). P. grandiflora germ. 70(80% in 3-4 d) and 40(90% in 3rd. w). Light had no effect. Seed DS 6 m at 70 germ; less, 70(2%) and 40(5%).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Phacelia p. 191. 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, 1993

Difficulty Very 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. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: either

about 6 months from start to sowing. Germination time not stated; 21 days assumed.

2% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Phacelia p. 191Public domain
Show the original text
Phacelia (Hydrophyllaceae). P. grandiflora germ. 70(80% in 3-4 d) and 40(90% in 3rd. w). Light had no effect. Seed DS 6 m at 70 germ; less, 70(2%) and 40(5%).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Phacelia p. 191. 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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