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Philadelphus coronarius

European Mock-orange · Mock Orange · Philadelphia Mock-orange · Sweet Mock Orange

Family HydrangeaceaeGenus Philadelphus

White four-petalled flowers with pale yellow stamens, opening in loose clusters along arching leafy branches.
FlowerNo machine-readable author provided. Rainer Bielefeld assumed (based on copyright claims).Public domain

About the plant

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

The plant

Habit
ShrubExtension Gardener Plant Toolbox
Habit
shrubPlants of the World Online
Height
10-12 ft3-3.7 mExtension Gardener Plant Toolbox
Spread
8-10 ft2.4-3 mExtension Gardener Plant Toolbox
Flower
WhitePLANTS Database
Blooms
Spring, SummerExtension Gardener Plant Toolbox
Native range
North Caucasus, Transcaucasus, TürkiyeGBIF Backbone Taxonomy
Hardiness zones
4-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Adapted to fine textured soilsPLANTS Database
Soil pH
5.3-7.5PLANTS Database
Moisture
Good DrainageExtension Gardener Plant Toolbox
Watering
Drought tolerance: LowPLANTS Database

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

Sources: Extension Gardener Plant Toolbox — NC State Extension; Plants of the World Online — Royal Botanic Gardens, Kew; PLANTS Database — USDA NRCS; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

This source reports 6 treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Moderate 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. 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

about 9 months from start to step 3. Germination happens during step 3; time not stated, 21 days assumed.

68% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Philadelphus p. 191Public domain
Show the original text
Philadelphus (Saxifragaceae). P. coronarius germ. better after DS. Seed DS 6 m 70 germ. 70(58% in 5-25 d) and 40-70(57% in 3-20 d). Fresh seed germ. 70(2%)-40-70(41%) and 40-70(14%)-40-70. Seed DS 6 m 40 germ. 70(16%) and 40- 70(68%) showing an intermediate behavior.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Philadelphus 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 Moderate Rated by us, not by the source.

Start around September 13, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 12, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C

about 6 months from start to sowing. Then 25 days to germinate.

58% germination in 5–25 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Philadelphus p. 191Public domain
Show the original text
Philadelphus (Saxifragaceae). P. coronarius germ. better after DS. Seed DS 6 m 70 germ. 70(58% in 5-25 d) and 40-70(57% in 3-20 d). Fresh seed germ. 70(2%)-40-70(41%) and 40-70(14%)-40-70. Seed DS 6 m 40 germ. 70(16%) and 40- 70(68%) showing an intermediate behavior.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Philadelphus 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 Moderate Rated by us, not by the source.

Start around June 20, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 19, 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

about 9 months from start to step 3. Germination happens during step 3, in 20 days.

57% germination in 3–20 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Philadelphus p. 191Public domain
Show the original text
Philadelphus (Saxifragaceae). P. coronarius germ. better after DS. Seed DS 6 m 70 germ. 70(58% in 5-25 d) and 40-70(57% in 3-20 d). Fresh seed germ. 70(2%)-40-70(41%) and 40-70(14%)-40-70. Seed DS 6 m 40 germ. 70(16%) and 40- 70(68%) showing an intermediate behavior.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Philadelphus 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 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 germinated in this phase.

  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.

41% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Philadelphus p. 191Public domain
Show the original text
Philadelphus (Saxifragaceae). P. coronarius germ. better after DS. Seed DS 6 m 70 germ. 70(58% in 5-25 d) and 40-70(57% in 3-20 d). Fresh seed germ. 70(2%)-40-70(41%) and 40-70(14%)-40-70. Seed DS 6 m 40 germ. 70(16%) and 40- 70(68%) showing an intermediate behavior.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Philadelphus 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 5

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. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C

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

16% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Philadelphus p. 191Public domain
Show the original text
Philadelphus (Saxifragaceae). P. coronarius germ. better after DS. Seed DS 6 m 70 germ. 70(58% in 5-25 d) and 40-70(57% in 3-20 d). Fresh seed germ. 70(2%)-40-70(41%) and 40-70(14%)-40-70. Seed DS 6 m 40 germ. 70(16%) and 40- 70(68%) showing an intermediate behavior.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Philadelphus 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 6

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around December 15, 2026 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

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

Steps after step 2 run on after germination.

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

14% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Philadelphus p. 191Public domain
Show the original text
Philadelphus (Saxifragaceae). P. coronarius germ. better after DS. Seed DS 6 m 70 germ. 70(58% in 5-25 d) and 40-70(57% in 3-20 d). Fresh seed germ. 70(2%)-40-70(41%) and 40-70(14%)-40-70. Seed DS 6 m 40 germ. 70(16%) and 40- 70(68%) showing an intermediate behavior.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Philadelphus 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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