

Oregon Geranium Geranium oreganum
Oregon Geranium is a perennial wildflower native to Canada and the lower 48 states. It grows to 3 ft and blooms Apr in full sun, with brown fruit. A host for pollen-specialist native bees.
More about this plant
Geranium oreganum is a species of geranium known by the common name Oregon cranesbill, or Oregon geranium. It is native to western North America from California to Alberta, where it grows in mountain forests and meadows. This is a perennial herb growing generally erect to heights of 40 to 80 centimeters. The slender stems have a foliage of large palmate leaves up to 15 centimeters wide and divided into several segments, each of which is subdivided into rounded or pointed lobes. The flower has pointed sepals beneath rounded lavender to purple petals. The fruit has a small body with a pointed style column up to five centimeters long. Wikipedia →
Growing & care
USDA PLANTS · TRY- Sun
- Full sun
- Soil & moisture
- High moisture
- Soil pH
- 7–8
- Fertility need
- Low
- Adapts to
- Medium (loam), Fine (clay)
- Hardiness
- USDA zone 8+
- Height
- 3 ft
- Mature width
- ~ 2 ft wide DERIVED derived estimate — open-grown crown allometry (height × growth-form ratio); not a measurement
- Spread
- None — clumping
- Growth rate
- Rapid
- Growth form
- Single stem
- Lifespan
- Perennial · short-lived
- Foliage
- Broadleaf · medium texture
- Active growth
- Spring & summer
- Fruit
- Brown
- Flower colour
- Purple AI AI image-analysis of community-science photos (~87% expert agreement) — not a botanical record
- Propagate by
- Seed
- Seed starting
- Needs cold stratification a cold-moist spell before it germinates
- Seeds ripen
- Summer – Autumn seed-collection / harvest window
- In the trade
- No known commercial source
- Deer browsing
- Medium moderately palatable
- Resprouts if cut
- No
Sow timing keys off your local last- and first-frost dates.
Wildlife & pollinators
How pollinator value is scored →❧ Caterpillar hosts ~24 caterpillar species
Geranium supports ~24 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 Geranium in North America, including:
+ 8 more species → ↑ show fewer
✦ Bees specialist-bee host · 1 bee visitor
Specialist native bees depend on it.
Some native bees are pollen specialists (oligolectic) — they raise young only on pollen from particular plant genera. Geranium is a recorded specialist-bee host, so losing it can mean losing the bee that relies on it.
1 native & managed bee species is documented visiting Oregon Geranium :
How we know this (3) Methods & honest limits
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.
For woody plants that have a height but no measured crown, we estimate width = height × a crown-to-height ratio fit for that plant’s form (conifers narrower than broadleaf trees, shrubs widest), calibrated on our measured open-grown crowns and capped at the largest one ever measured. A measured crown always wins; herbaceous plants get nothing (no anchor).
Honest limits: A coarse class-median estimate for garden-scale spacing, not a measurement; woody single/multi-stem forms only.
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 (31) 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).
Loading…
BibTeX
Loading…