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Phlox longifolia

Long-leaved Phlox · Longleaf Phlox

Family PolemoniaceaeGenus Phlox

A rounded cushion of narrow leaves smothered in pale pink flowers, each with a small yellow eye, on pale sandy ground.
The whole plantWallace KeckPublic domain

About the plant

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

The plant

Habit
subshrubPlants of the World Online
Habit
Perennial, Forb/herb, SubshrubPLANTS Database
Height
1.2 ft35 cmPLANTS Database
Flower
PurplePLANTS Database
Blooms
Late SpringPLANTS Database
Native range
Canada, lower 48 statesPLANTS Database

Growing conditions

Sun
Shade tolerance: MediumPLANTS Database
Soil
Adapted to coarse, medium textured soilsPLANTS Database
Soil pH
6.5-8.5PLANTS Database
Moisture
Moisture use: LowPLANTS Database
Watering
Drought tolerance: HighPLANTS Database

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.

Worth knowing

  • Longleaf phlox grows from British Columbia through the western United States but is absent west of the Cascades. It favors dry, open places such as slopes, rocky ground and plains. Wikipedia: Phlox longifolia

This source reports two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Low Rated by us, not by the source.

Start around March 8, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Temperature: 40°F 4°C

Germination happens during step 1, in 28 days.

100% germination in 14–28 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Phlox p. 191Public domain
Show the original text
Phlox (Polemonlaceae). Phlox seed is hard to collect as there are only a few seed in each spherical capsule and these capsules roll away as soon as ripe. As a result seed of Phlox is not readily available except for the annual P. longifolia germ. 40(100% in 2-4 w, largely in 2nd w) and 70(24% in 7-10 w)- 40(76% in 2nd w).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Phlox 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 December 22, 2026 for a May 3 last frost.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    24 germinated in this phase.

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 3 months from start to step 2. Germination happens during step 2, in 14 days.

76% germination in 14 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Phlox p. 191Public domain
Show the original text
Phlox (Polemonlaceae). Phlox seed is hard to collect as there are only a few seed in each spherical capsule and these capsules roll away as soon as ripe. As a result seed of Phlox is not readily available except for the annual P. longifolia germ. 40(100% in 2-4 w, largely in 2nd w) and 70(24% in 7-10 w)- 40(76% in 2nd w).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Phlox 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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