Rhododendron, Oregon, sits in USDA hardiness zone 7b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Expect cabbage, prickly pear, california poppy, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Rhododendron, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Rhododendron lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Rhododendron — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Rhododendron — the short answer
Rhododendron, Oregon: USDA zone 7b, about 195 days between hard freezes, across 3K acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~195
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 3K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 7b is Rhododendron's average, not your lot's — a low corner or a tree line moves it. Against Rhododendron's 195-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Rhododendron
Each reading below is measured for Rhododendron itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRhododendron runs about 195 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredRhododendron sits in USDA hardiness zone 7b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Rhododendron is in
Rhododendron sits in the Cascades — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Rhododendron's own centroid rather than borrowed from Clackamas County.
What Grows in Rhododendron
Every plant below cleared Rhododendron's own zone 7b and its 195-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in Rhododendron?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 4 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Rhododendron
Survey cells within 31 miles of Rhododendron checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 523 miles off. What to watch for.
What's on the federal record near Rhododendron
Closest first, within ~10 miles of Rhododendron. Listing isn't leaking, and distance isn't exposure.
- MT HOOD GENERAL STOREUnderground Storage Tanks · 2.7 mi
- SERVICE STATIONUnderground Storage Tanks · 3.5 mi
- HI SKI CORPUnderground Storage Tanks · 3.6 mi
- SUMMIT CFNUnderground Storage Tanks · 4.0 mi
- THUNDERHEAD LODGE CONDOMINIUMSUnderground Storage Tanks · 4.1 mi
- RLK & COMPANY - TIMBERLINE LODGEUnderground Storage Tanks · 4.4 mi
- TIMBERLINE LODGE - LOWER SHOPUnderground Storage Tanks · 4.4 mi
- TIMBERLINE LODGEUnderground Storage Tanks · 4.4 mi
- CENTURYTEL OF EASTERN OREGON, INC.Underground Storage Tanks · 4.4 mi
- RLK & COUnderground Storage Tanks · 4.4 mi
- RLK COMPANYUnderground Storage Tanks · 4.4 mi
- SUMMIT CHEVRONUnderground Storage Tanks · 4.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Rhododendron's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Rhododendron.
Sources Checked
within ~10 miles of Rhododendron
Severity Distribution
within ~10 miles of Rhododendron
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rhododendron, Underground Storage Tanks runs higher than the national average — 35 sites within ~10 miles of Rhododendron. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Rhododendron
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Rhododendron average
Your land is one point inside Rhododendron
Everything above resolves to Rhododendron as a whole — one PHZM band and one 28°F frost record, read across 3K acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the Rhododendron Average
Rhododendron Average
- ●USDA Zones 7b, averaged across Rhododendron
- ●One soil character for all of Rhododendron
- ●Frost dates read at Rhododendron's scale: Apr 23 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Rhododendron's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Rhododendron
Pull a site-specific report for your exact address in Rhododendron, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Rhododendron averages can't show:
We read public map data around Rhododendron — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rhododendron average
How we know this about Rhododendron
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Rhododendron’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Rhododendron
When does frost risk typically end in Rhododendron?
The last hard freeze (28°F) in Rhododendron typically lands around Apr 23, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about May 14.
When is the first frost in Rhododendron?
The first hard freeze (28°F) in Rhododendron typically arrives around Nov 4, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 21, so the watching starts about Oct 5 — about 195 days after the spring freeze cleared.
How long is the growing season in Rhododendron?
Measured between 28°F hard freezes, Rhododendron sees about 195 frost-free days — roughly Apr 23 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 14 to Oct 21, about 160 days.
Is the soil safe to grow vegetables in Rhododendron?
The federal record around Rhododendron shows 42 documented sites, mostly Underground Storage Tanks entries (35), the nearest Underground Storage Tanks record about 2.7 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Rhododendron?
From about Oct 5 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 4 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 4. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Rhododendron's scale — its 7b band and its 195-day season. Your yard writes its own version of Rhododendron's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Rhododendron’s own scale
7 of the readings below were taken at Rhododendron's own scale — its own ~195-day season between 28°F freezes, the 2,500 acres it covers and 42 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Rhododendron's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Rhododendron's own 28°F hard-freeze dates, about Apr 23 and Nov 4 and the ~195-day span between themNOAA 1991–2020 Climate Normals
- 42 documented contamination sites on the federal record near Rhododendron, the closest Underground Storage Tanks record about 2.7 miles out from the town centreFederal environmental registers
- Rhododendron's boundary and the 2,500 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~195-day seasonGrowable Ground crop-matching engine
- The ecoregion at Rhododendron's own centroid, the CascadesUS EPA Level III Ecoregions
- Lanternfly survey cells around Rhododendron checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Rhododendron's 2,500 acres read through its county's SSURGO summaryfrom Clackamas County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Clackamas County
- The growing challenges every Oregon grower plans around — written at state scale, so they stay on the state guidefrom Oregon
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Clackamas County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Rhododendron's 2,500 acreswhy one lot differs from the next →
- Which side of Rhododendron you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,500 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 2.7 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Rhododendron-wide figureread your own land →