Mendel’s Gardens

Sabatia kennedyana

Plymouth Rose Gentian · Plymouth Gentian · Large Sabatia

Family GentianaceaeGenus Sabatia

About the plant

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

The plant

Habit
Herbaceous perennialPlant Finder
Habit
Perennial, Forb/herbPLANTS Database
Height
2.5-3 ftPlant Finder
Spread
2.5-3 ftPlant Finder
Flower
Showy; pink and white with a yellow and red eyePlant Finder
Blooms
June to AugustPlant Finder
Native range
Eastern North AmericaPlant Finder
Native range
Canada, lower 48 statesPLANTS Database
Hardiness zones
6-9Plant Finder
Note
Sowing at 40 is fatal -- nothing over three cycles. A cold period after germination is fine.Seed Germination Theory and Practice, 2nd ed.
Note
A wetland species. Wild populations are threatened by shoreline development and poaching.Plant Finder

Growing conditions

Sun
Full sun
Soil
Wet, boggy
Moisture
Wet
Watering
Wet

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 Database — USDA NRCS; Seed Germination Theory and Practice, 2nd ed. — N. C. Deno.

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 1, 2027 for a May 3 last frost.

  1. Warm moist stratification

    Temperature: 70°F 21°C

    42%, over 2-5 weeks.

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    Deno gives no length for this period; three months is his standard cycle.

  3. Warm moist stratification

    Temperature: 70°F 21°C

    A further 30%, in 6-8 days.

Steps after step 1 run on after germination.

No stated waiting before sowing. Then 35 days to germinate.

42% germination in 14–35 days.

42% at 70, then 30% more after the cycle. Sow warm: sowing at 40 kills it.

This source doesn't state how long.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, SabatiaPublic domain
Show the original text
Sabatia ( Gentianaceae). S. kennedyana germ. 70(42% in 2-5 w)-40-70(30% in 6-8 d) and none at 40 even after 3 cycles showing that sowing at 40 is fatal.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Sabatia. 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
  1. Cold moist stratification

    Temperature: 40°F 4°C

    Nothing, even after three cycles.

No stated waiting before sowing.

0% germination.

Nothing over three cycles. Deno calls sowing at 40 fatal for this species.

This source doesn't state how long.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, SabatiaPublic domain
Show the original text
Sabatia ( Gentianaceae). S. kennedyana germ. 70(42% in 2-5 w)-40-70(30% in 6-8 d) and none at 40 even after 3 cycles showing that sowing at 40 is fatal.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Sabatia. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list.