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Liliaceae family

Douglas' Onion Allium douglasii

Native
Deer favourite — Rated highly palatable to browsing deer — so where deer are around, expect this one to get nibbled. It's a documented preference, not a certainty: pressure swings with the place and season, and a fenced or low-deer yard may be untouched.

Douglas' Onion is a perennial wildflower native to the lower 48 states. It grows to 0.9 ft and blooms May in part shade – shade, with brown fruit.

More about this plant

Allium douglasii, the Douglas' onion, is a perennial herbaceous flowering plant in the Amaryllidaceae family. It is native to northeastern Oregon, eastern Washington, and northern Idaho. Wikipedia →

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
USDA PLANTS — Sun · Soil & moisture
USDA — SoilPH — Soil pH
USDA PLANTS (DwCA, Zenodo 17903503) — Fertility Requirement / Soil Adaptation — Fertility need · Adapts to
USDA — Temp-Min °F — Hardiness
Sun
Part shade – shade
Soil & moisture
Medium moisture
Soil pH
6–7.8
Fertility need
Low
Adapts to
Coarse (sandy), Medium (loam), Fine (clay)
Hardiness
USDA zone 5+
Size & form
Sources · Size & form
USDA PLANTS (DwCA, Zenodo 17903503) — Height, Mature — Height
USDA PLANTS (DwCA, Zenodo 17903503) — Planting Density (per acre) — Spacing
USDA PLANTS (DwCA, Zenodo 17903503) — Growth Rate / Spread / Growth Form / Lifespan / Active Growth Period / Seed Period — Spread · Growth rate · Growth form · Active growth
USDA PLANTS — Lifespan
TRY Plant Trait Database (CC BY 4.0) · USDA PLANTS — Foliage
USDA PLANTS (DwCA, Zenodo 17903503) — Fruit/Seed Color / Fruit Persistence — Fruit
Height
0.9 ft
Spacing
2–3 ft apart from USDA planting density
Spread
Slow
Growth rate
Rapid
Growth form
Single crown
Lifespan
Perennial · short-lived
Foliage
Broadleaf · medium texture
Active growth
Spring
Fruit
Brown
In the garden
Sources · In the garden
USDA PLANTS (DwCA, Zenodo 17903503) — Propagation Method / Commercial Availability — Propagate by · In the trade
USDA PLANTS (DwCA, Zenodo 17903503) — Germination (cold stratification) — Seed starting
USDA PLANTS — Seed Period — Seeds ripen
USDA PLANTS (DwCA, Zenodo 17903503) — Foliage Texture / Browse Palatability / Resprout — Deer browsing · Resprouts if cut
Propagate by
Seed, Bulbs
Seed starting
No stratification needed
Seeds ripen
Spring – Summer seed-collection / harvest window
In the trade
No known commercial source
Deer browsing
High browsed readily
Resprouts if cut
No
Ground-cover layer — Sits in the ground-cover of a layered food forest or polyculture.Open guide →
Living mulch / groundcover — Low, ground-hugging grower — can carpet bare soil as a living mulch, shading out weeds and holding moisture.Open guide →
derived roles
The garden year bloom → fruit → fall colour
J
F
M
A
M
J
J
A
S
O
N
D
Bloom
Bloom (the flower's colour)
Bloom · May — USDA PLANTS (DwCA, Zenodo 17903503) — BloomPeriod
When to sow · for your area

Sow timing keys off your local last- and first-frost dates.

Species characteristics from USDA PLANTS (public domain) + TRY (CC BY) — general guidance, not a guarantee for your exact site. Deer "browsing" is documented palatability, not a deer-proof claim.

Wildlife & pollinators

How pollinator value is scored →
❧ Caterpillar hosts ~21 caterpillar species

Allium supports ~21 caterpillar species.

Native butterfly & moth caterpillars are the base of the terrestrial food web — most songbirds rear their young almost entirely on them. As a host for native Lepidoptera this is a moderate genus.

Recorded feeding on Allium in North America, including:

Actebia fennica · owlet moth Aglossa caprealis · Meal Moth Agrotis gladiaria · Swordsman Dart Agrotis ipsilon · Dark Sword-Grass Agrotis malefida · Rascal Dart Agrotis orthogonia · Pale Western Cutworm
+ 8 more species →
Archips argyrospila · Fruit-Tree Leafroller Moth Autographa californica · Alfalfa Looper Moth Cadra cautella · Fig-Moth Cadra figulilella · snout moth Cryptoblabes gnidiella · snout moth Discestra trifolii · owlet moth Ephestia elutella · snout moth Estigmene acrea · Salt Marsh Moth
Keystone count (genus-level) from Warren II 2026 (CC0) · Tallamy host-use records. Named species (a documented Nearctic sample, not exhaustive) from NHM HOSTS (CC0).
Species thumbnails re-hosted from iNaturalist — Creative Commons, credited per image (hover for credit). Click any species to see it on iNaturalist. Not exhaustive; many taxa have no openly-licensed photo yet.
How we know this (2) Methods & honest limits
Photosynthesis Direct fact

A recorded categorical fact: each species is tagged C3 (standard), C4 (heat/water-efficient) or CAM (succulent, night-time CO₂ uptake) — or a facultative combination. We only show a trait card for the noteworthy C4/CAM cases; C3 is the unremarkable majority, kept in the data but not surfaced as a card.

Kattge, J. et al. TRY plant trait database — Categorical Traits Dataset (2012).
Climate niche (heat tolerance & native rainfall) Derived

We take the plant’s U.S. county range and look up each county’s long-term climate, then summarise: native rainfall = the median annual rainfall across its counties; heat tolerance = the warm end (90th percentile) of average temperature across its range (mirroring how our cold-hardiness floor uses an extreme). Counties + medians blunt the roadside/observer bias that makes point-level climate unreliable. Needs at least five placeable counties.

Honest limits: A realized, sampling-biased niche (where it has been recorded, not its physiological optimum), and county climate is coarse — large Western counties span deserts and mountains. Derived guide, never a measured fact.

Realized-niche / climate-envelope approach (Pearson & Dawson 2003; Soberón 2007). Climate: NOAA NCEI nClimDiv county normals (1991–2020).
Derived values are computed from open data by a published method — labelled, cited, and never shown as a direct observation. Full methodology →
Sources for this entry (28) Open & cited
[01] Scientific name & family — USDA PLANTS (DwCA, Zenodo 17903503)
[02] Growth habit & duration — USDA PLANTS (DwCA, Zenodo 17903503)
[03] Native status & distribution — USDA PLANTS (DwCA, Zenodo 17903503)
[04] Common name — USDA PLANTS (via GBIF)
[18] Invasive / introduced status — USDA PLANTS (DwCA, Zenodo 17903503) — native status
[19] Wetland indicator — USACE National Wetland Plant List (2022)
[21] Description — Wikipedia (CC BY-SA)
[22] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[24] Photosynthetic pathway — TRY Plant Trait Database (CC BY 4.0)
[25] Climate niche — Derived — realized climate niche from U.S. county occurrences (GBIF) × NOAA NCEI county climate normals 1991–2020 (public domain)
[26] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[27] Caterpillar species — NHM HOSTS (CC0)
[28] County range — GBIF Open Data — open-licensed occurrences (CC0/CC-BY) → county
Spot an error or have a better photo? Every field links to its source, and the whole dataset is open.
Cite this page Open data, please attribute

PlantKey’s data is open under CC BY-SA 4.0 — free to reuse and adapt, with attribution and the same licence. Photos keep their own per-image licence + credit (see Sources above).

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