Tolmie's Onion Allium tolmiei
Tolmie's Onion is a perennial wildflower native to the lower 48 states. It grows to 1 ft and blooms Mar in part shade – shade, with brown fruit.
More about this plant
Allium tolmiei is a plant species native to Idaho, eastern and central Oregon, southeastern Washington, northwestern Nevada and northeastern California. It occurs on mountains and scrublands at elevations of 1,300–9,200 feet (400–2,800 m). It was discovered by and named for Dr. William Fraser Tolmie. Wikipedia →
Growing & care
USDA PLANTS · TRY- Sun
- Part shade – shade
- Soil & moisture
- Medium moisture
- Soil pH
- 6–8
- Fertility need
- Low
- Adapts to
- Coarse (sandy), Medium (loam), Fine (clay)
- Hardiness
- USDA zone 4+
- Height
- 1 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
- Flower colour
- Pink AI AI image-analysis of community-science photos (~87% expert agreement) — not a botanical record
- Propagate by
- Seed, Bulbs
- Seed starting
- No stratification needed
- Seeds ripen
- Spring – Summer seed-collection / harvest window
- In the trade
- Contract growing only
- Deer browsing
- High browsed readily
- Resprouts if cut
- No
Sow timing keys off your local last- and first-frost dates.
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:
+ 8 more species → ↑ show fewer
Related plants
More Allium →
How we know this (3) Methods & honest limits
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.
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.
McKenzie et al. assigned each species a flower colour with a GPT-4V vision model over iNaturalist photos. We use the confident tier plus a separately-labelled lower-confidence top-up (mostly inconspicuous green/brown flowers), and render it as a small tint — never as an asserted fact, and kept out of the written synopsis.
Honest limits: AI image inference (~87% expert agreement on the confident tier); a decorative, confidence-tiered indicator, not a measured trait.
Sources for this entry (30) Open & cited
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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