Unlikely — Zone Mismatch
philodendron (zones 11-12) does not overlap with Oregon's zone range (5a-10a). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Philodendron is hardy to zone 11, and the warmest ground in Oregon is zone 9 — 2 zones short. Planted in open ground it will not survive a Oregon winter. To grow it here, grow philodendron in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.
An earth-sheltered greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 11-12 (plant) against 5-9 (Oregon). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.
Philodendron in Oregon — the short answer
Philodendron in Oregon: hardy in zones 11–12, part sun, against a state median of ~213 frost-free days.
- Plant zones
- 11-12
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Oregon zones
- 5a-10a
- USDA PHZM 2023
- Frost window
- Feb 25 - Apr 26 – Oct 19 - Nov 26
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 86 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.
Your yard isn't the whole zone.
Oregon spans zones 5a-10a, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score philodendron against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Oregon is not one climate
A single Oregon answer averages 36 counties whose growing seasons are 222 days apart — from 86 frost-free days in Klamath County to 308 in Lincoln County. Which end of that your land sits nearer changes what philodendron can finish before the first hard freeze.
The middle half of 36 counties runs 165–274 days, with a median of 212 days — a 222-day span end to end.
Measured across 36 Oregon counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.
Where Philodendron Stands in Oregon
Philodendron is rated for zones 11–12 — a cold floor USDA puts at 40 to 50°F. No Oregon county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Oregon winters, not about philodendron.
Below the zone 11 floor
36 counties
- Klamath County · zone 6a
- Baker County · zone 6b
- Crook County · zone 6b
3 of 36 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Zone Comparison
Philodendron Needs
- USDA Zones: 11-12
- Frost-Free Days: 365+
- Sun: Part Sun
- Mature size: 4 ft tall
- Drought tolerance: Medium
Oregon Has
- USDA Zones: 5a-10a
- Last Hard Freeze (28°F): Feb 25 - Apr 26
- First Hard Freeze (28°F): Oct 19 - Nov 26
- Annual Rainfall: 8-90 inches
- Common Soils: Volcanic, Silt loam (Willamette), Sandy loam
Plant Zone Range (zones 11-12)
Preferred Soil pH
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Philodendron in Oregon
The frost window
Across Oregon, the last spring hard freeze (28°F) clears between Feb 25 and Apr 26, and the first fall hard freeze lands between Oct 19 and Nov 26 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 176-day window you can count on — up to 274 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.
Timing tuned to sub-state frost dates — Klamath County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
The zone check says philodendron does not survive a Oregon winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on Oregon under protection.
Frost-free days
Philodendron wants 365+ frost-free days; a typical Oregon site sees ~213 (NOAA Regional Climate Centers ACIS, 1991-2020) — 152 days short of what it needs. A typical Oregon season does not carry this crop to harvest outdoors, and a gap that size is not one an earlier sowing date or a faster cultivar closes; growing it here means growing it under cover.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.
Soil + Drainage Fit
Philodendron likes near-neutral soil (pH 5-7.5). That's the common-ground band across Oregon's volcanic and silt loam (willamette) — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 5.5 and 6 — worth knowing before you decide whether a Oregon soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Oregon site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Oregon's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Philodendron needs about 59 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how philodendron performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Oregon soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Philodendron in Oregon
Zone compatibility tells you about winter cold survival — but Oregon growers also need to think about:
West side: excessive rain and overcast skies reduce sun for warm-season crops
East side: arid conditions (8-15 inches rainfall) require irrigation
Slug pressure is extreme in western Oregon
Mountain areas have very short seasons (60-90 frost-free days)
Growing philodendron here specifically
Oregon's soils run mostly silt loam (Mollisols), and whether that suits philodendron's pH 5.0–7.5 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward philodendron's 5.0–7.5 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every Oregon grower, not just philodendron — is covered on the Oregon growing guide.
Timing shifts within Oregon
Oregon isn't one climate. In Klamath County, the last hard freeze (28°F) holds until about Jun 9 — roughly 67 days later than the recorded state median — so plant philodendron to your county's window, not the statewide date.
Philodendron needs about 365 days of frost-free season to complete its cycle. No Oregon county gives it that outdoors: even Lincoln County, the state’s longest season at 308 frost-free days, falls 57 days short — so it needs transplants, a short-season variety, or covered growing.
Across Oregon’s 36 counties the frost-free season runs from 86 days in Klamath County to 308 days in Lincoln County — a spread of 222 days, which is why a single statewide planting date misleads. The median Oregon county sees 213 frost-free days, which is 152 days short of what philodendron needs — so on a typical Oregon parcel this is a transplant-or-protect crop, not a direct-sow one.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Philodendron's 365-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Good to Know Before You Plant Philodendron
Philodendron is listed as toxic to dogs, cats (all) at a moderate level (ASPCA). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear. Parts of philodendron carry moderate toxicity for people, so know which parts are edible before harvest. Worth knowing for placement: in Oregon this is a one-season plant and the first hard freeze (Oct 19 - Nov 26) takes it down, so the exposure above is a summer-long one rather than something standing in the bed all year.
Oregon Cooperative Extension
For Oregon-specific cultivar recommendations, planting calendars, and pest pressure for philodendron, the canonical source is OSU Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Philodendron native to Oregon?
No — the USDA PLANTS Database lists Philodendron as introduced rather than native in the Lower 48, so it is not part of Oregon's native flora. It grows here as a garden plant; pairing it with a few Oregon natives keeps local pollinators fed too.
Looking for plants that belong here? The Oregon growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Philodendron in Oregon
When can I plant Philodendron in Oregon?
Oregon's last spring hard freeze (28°F) clears between Feb 25 and Apr 26, and the first fall hard freeze lands between Oct 19 and Nov 26 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
What hardiness zone is Philodendron grown in across Oregon?
Oregon spans USDA hardiness zones 5a-10a (USDA ARS PHZM 2023). Philodendron carries a range of zones 11-12, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Oregon site have?
A typical Oregon site sees ~213 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Philodendron needs 365+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Klamath, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Philodendron native to Oregon?
No — the USDA PLANTS Database lists Philodendron as introduced rather than native in the Lower 48, so it is not part of Oregon's native flora. It grows here as a garden plant; pairing it with a few Oregon natives keeps local pollinators fed too.
How should I amend the soil for Philodendron in Oregon?
Philodendron prefers pH 5-7.5 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Oregon soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Philodendron actually grow on my specific land in Oregon?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores philodendron against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Oregon
State-level data is a sketch. Your Growable Ground report scores philodendron against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Oregon philodendron averages can't show:
We read public map data around Oregon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Oregon philodendron average
Explore More
Growing guides for philodendron
Explore Oregon county by county
Oregon carries 36 counties with their own USDA zone — a sample of the growing pages for philodendron there:
Where else philodendron grows
Philodendron's zone band crosses state lines — these are the states closest to Oregon in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Oregon
Oregon has a growing page for 1,038 plants — a rotating sample of the rest of the shelf.
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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