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Paeonia × suffruticosa

Tree Peony · Moutan Peony

Family PaeoniaceaeGenus Paeonia

A white peony opened wide, its many crumpled petals around a dense ring of cream stamens and a pale central ovary.
Flower池田正樹 (talk)masaki ikedaPublic domain

About the plant

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

The plant

Habit
Deciduous shrubPlant Finder
Habit
shrubPlants of the World Online
Height
3-5 ft0.9-1.5 mPlant Finder
Spread
3-4 ft0.9-1.2 mPlant Finder
Flower
Showy; pink to white with purple basal petal patchesPlant Finder
Blooms
April to MayPlant Finder
Native range
China, Tibet, BhutanPlant Finder
Hardiness zones
4-8Plant Finder
Note
Nicking the seed, reported to help in the first edition, did not hold up. GA-3 gave only a small gain.Seed Germination Theory and Practice, 2nd ed.

Growing conditions

Sun
Full sun to part shadePlant Finder
Soil
Deep, fertile, medium moisture, well-drainedPlant Finder
Watering
MediumPlant Finder

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

Sources: Plant Finder — Missouri Botanical Garden; Plants of the World Online — Royal Botanic Gardens, Kew; Seed Germination Theory and Practice, 2nd ed. — N. C. Deno.

Worth knowing

  • Grown in China for millennia, at first only as medicine for the skin of its roots. In China it is the king of flowers, and in 1903 the Qing government named it the national flower. Wikipedia: Paeonia × suffruticosa

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 March 21, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 20, 2026.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    14% here.

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    A further 16%.

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    35% -- the largest flush.

  5. Cold moist stratification

    Temperature: 40°F 4°C

    A last 11%.

about 12 months from start to step 5. Germination happens during step 5; time not stated, 21 days assumed.

35% germination.

14, 16, 35 and 11 per cent over four cycles -- about three quarters of the seed in all.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, PaeoneaPublic domain
Show the original text
Paeonea (Ranunculacèae). Nicking the seeds of P. officinalis and P. suffruticosa was reported to give some promotion to germination in the first edition, but this has not been confirmed in later and more extensive experiments. P:anomala, emodi, lutea, mlkosewetschii, obovata, and vernalis germ. at 70. similar to P.officinalis. Germination consists of forming a radicle and a branching root system. This requires about 2 m after which the seedlings are given 3 m at 40. On shifting back to 70 the true leaf forms (hypogeal). Germination was hypogeal in all but P. brownii,tand all germ. at 70 except P. broteri and P. brownii. These germ. at 40. Treatment with GA-3 gave a small increase in rate of germination in P. officinalis and P. suffruticosa. P. suffruticosa germ. at 70 in an approximate first order rate with an ind. t of 40 d and a half life of 11 d. These numbers are very close to those for P. off icinalis. Some specific data are 70(25% in 4th m)-40(5%)-70(30% on 3rd d) and 40-70(14%)-40(16%)-70(35%)-40(11%) using fresh seed.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Paeonea. 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 January 2, 2027 for a May 3 last frost.

  1. Warm moist stratification

    Temperature: 70°F 21°C

    25% here, in the fourth month. The radicle and its branching root system form here. This is what Deno counts as germination.

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    A further 5%.

  3. Warm moist stratification

    Temperature: 70°F 21°C

    30% on the third day. The single true leaf forms only now. Germination is hypogeal.

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

30% germination in 3 days.

25% in the fourth month, 5% in the cold, then 30% on the third day back at 70.

This source doesn't state how long step 1 lasts.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, PaeoneaPublic domain
Show the original text
Paeonea (Ranunculacèae). Nicking the seeds of P. officinalis and P. suffruticosa was reported to give some promotion to germination in the first edition, but this has not been confirmed in later and more extensive experiments. P:anomala, emodi, lutea, mlkosewetschii, obovata, and vernalis germ. at 70. similar to P.officinalis. Germination consists of forming a radicle and a branching root system. This requires about 2 m after which the seedlings are given 3 m at 40. On shifting back to 70 the true leaf forms (hypogeal). Germination was hypogeal in all but P. brownii,tand all germ. at 70 except P. broteri and P. brownii. These germ. at 40. Treatment with GA-3 gave a small increase in rate of germination in P. officinalis and P. suffruticosa. P. suffruticosa germ. at 70 in an approximate first order rate with an ind. t of 40 d and a half life of 11 d. These numbers are very close to those for P. off icinalis. Some specific data are 70(25% in 4th m)-40(5%)-70(30% on 3rd d) and 40-70(14%)-40(16%)-70(35%)-40(11%) using fresh seed.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Paeonea. 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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