Phlox diffusa Benth.

vernacular spreading phlox — species · Polemoniaceae

USDA: PHDI3
GBIF: 2927749
Rank: species

spreading phlox (Phlox diffusa) — Platephotograph · MARS MonitoringCC BY-NC source · iNaturalist ↗

§2Habit & range

Growth habit: Forb/herb, Subshrub
Duration: Perennial
Group: Dicot
Family: Polemoniaceae Juss.
Genus: Phlox

§2a

Native status, by region

CAN Canada Native
L48 Lower 48 States Native

§2b

County-level range

· 4 counties across 1 state

Legend Native · 4 Introduced · 0 Both · 0 Hover a county for detail.

§3Cultivation specs · USDA

Recorded by the USDA Plant Materials Program.

§3a

Tolerances

Drought: High
Shade: Low
Moisture use: Low
Fire: Medium
Salinity: None
Anaerobic: None
CaCO₃: Medium
Hedging: None

§3b

Climate & soil

Cold tolerance: -13 °F minimum
Frost-free days: 120 min.
Precipitation: 20–40 in/yr
pH range: 6.5–8.5
Root depth: 15 in min.
Fertility need: Low
Soil texture: coarse, medium

§3c

Form & growth

Growth form: Single Crown
Growth rate: Slow
Lifespan: Moderate
Mature height: 0.5 ft
Foliage texture: Coarse
Foliage colour: Green
Porosity (summer): Dense
Porosity (winter): Moderate
Flower colour: Purple
Fruit colour: Brown
Fire resistant: No
N fixation: None
Toxicity: None

§3d

Reproduction

Bloom period: Late Spring
Seed abundance: Medium
Seed begins: Summer
Seed ends: Summer
Spread rate: Slow
Stratify: Yes
Propagation: seed, container, sprigs

§3e

Use & availability

Commercial availability: Routinely Available
Nursery stock: No
Browse palatability: Low
Graze palatability: Low
Palatable, human: No
Protein potential: Low
Lumber: No
Christmas tree: No

§4Counties, by state

Recorded in 4 counties across 1 state.

Montana view state ↗ 4 N ▾

§5Sources & provenance

USDA PLANTS

Symbol, taxonomy, distribution, cultivation specs, native status. Public domain.

plants.usda.gov/PHDI3 ↗

GBIF Backbone

Canonical taxonomic identity, synonym resolution, cross-refs. CC0.

gbif.org/species/2927749 ↗

Record version

Cached and built locally. Source version on this record:

usda-plants-mt-2026-05-25

fetched 2026-05-25T18:27:19Z