Deno’s GardenMy Garden

Hibiscus syriacus

Rose of Sharon · Shrub Althea

Family MalvaceaeGenus Hibiscus

A lilac flower with a dark red eye and a white central column, a second bloom and a bud behind
FlowerWilhelm Zimmerling PARCC BY-SA 4.0

About the plant

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

The plant

Habit
Perennial, Shrub, TreeExtension Gardener Plant Toolbox
Habit
shrub or treePlants of the World Online
Height
8-12 ft2.4-3.7 mExtension Gardener Plant Toolbox
Spread
6-10 ft1.8-3 mExtension Gardener Plant Toolbox
Flower
Gold/Yellow, Pink, Purple/Lavender, WhiteExtension Gardener Plant Toolbox
Blooms
Spring, SummerExtension Gardener Plant Toolbox
Hardiness zones
5-9Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Moisture
Good Drainage, Moist, Occasionally Dry, Occasionally WetExtension Gardener Plant Toolbox

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.

Worth knowing

  • The national flower of South Korea, named in its national anthem. Its Korean name, mugunghwa, translates as eternal blossom that never fades. Wikipedia: Hibiscus syriacus
  • Syriacus because it had been collected from gardens in Syria, though it is native to east Asia. Wikipedia: Hibiscus syriacus

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 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

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

100% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hibiscus p. 153Public domain
Show the original text
Hibiscus (Malvaceae). H. syriacus showed similar behavior for fresh seed and seed DS 6 m at 70 when sown at 70 but a sharp difference when sown at 40. Both germ. immediately at 70 as shown by 70(90% in 4-6 d) for DS seed and 70(70% in 10-17 d) for fresh seed. However, when sown at 40, DS seed germ. 40(100% in 712 w) whereas fresh seed germ. 40-70(98% in 3-5 d);
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hibiscus p. 153. 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 December 31, 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

about 3 months from start to step 2. Germination happens during step 2, in 5 days.

98% germination in 3–5 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hibiscus p. 153Public domain
Show the original text
Hibiscus (Malvaceae). H. syriacus showed similar behavior for fresh seed and seed DS 6 m at 70 when sown at 70 but a sharp difference when sown at 40. Both germ. immediately at 70 as shown by 70(90% in 4-6 d) for DS seed and 70(70% in 10-17 d) for fresh seed. However, when sown at 40, DS seed germ. 40(100% in 712 w) whereas fresh seed germ. 40-70(98% in 3-5 d);
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hibiscus p. 153. 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 Low Rated by us, not by the source.

Start around October 2, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on October 1, 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 6 days to germinate.

90% germination in 4–6 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hibiscus p. 153Public domain
Show the original text
Hibiscus (Malvaceae). H. syriacus showed similar behavior for fresh seed and seed DS 6 m at 70 when sown at 70 but a sharp difference when sown at 40. Both germ. immediately at 70 as shown by 70(90% in 4-6 d) for DS seed and 70(70% in 10-17 d) for fresh seed. However, when sown at 40, DS seed germ. 40(100% in 712 w) whereas fresh seed germ. 40-70(98% in 3-5 d);
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hibiscus p. 153. 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 Low Rated by us, not by the source.

Start around March 19, 2027 for a May 3 last frost.

  1. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 17 days to germinate.

70% germination in 10–17 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hibiscus p. 153Public domain
Show the original text
Hibiscus (Malvaceae). H. syriacus showed similar behavior for fresh seed and seed DS 6 m at 70 when sown at 70 but a sharp difference when sown at 40. Both germ. immediately at 70 as shown by 70(90% in 4-6 d) for DS seed and 70(70% in 10-17 d) for fresh seed. However, when sown at 40, DS seed germ. 40(100% in 712 w) whereas fresh seed germ. 40-70(98% in 3-5 d);
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hibiscus p. 153. 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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