Rivergrove, Oregon, sits in USDA hardiness zone 9a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, artichoke, fig, california poppy, and cabbage all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Rivergrove, 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 Rivergrove 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 Rivergrove — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Rivergrove — the short answer
Rivergrove, Oregon: USDA zone 9a, about 242 days between hard freezes, across 111 acres of city.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 25
- Clackamas County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 22
- Clackamas County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~242
- Clackamas County normal — NOAA 1991–2020, nearest to this town
- City area
- 111 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Clackamas County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Rivergrove's average, not your lot's — a low corner or a tree line moves it. Against Rivergrove's 242-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Rivergrove
Each reading below is measured for Rivergrove itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsRivergrove runs about 242 days between hard freezes (read from Clackamas County, the closest normal to Rivergrove) — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredRivergrove sits in USDA hardiness zone 9a.
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 Rivergrove is in
Rivergrove sits in the Willamette Valley — EPA Level III, inside the wider Marine West Coast Forest. That is read at Rivergrove's own centroid, and it is not what its county reads: Clackamas County is mostly Cascades. The wider page above you is answering a different question about different ground.
What Grows in Rivergrove
Every plant below cleared Rivergrove's own zone 9a and its 242-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in Rivergrove?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 22 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Rivergrove
Survey cells within 31 miles of Rivergrove checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 528 miles off. What to watch for.
What's on the federal record near Rivergrove
Closest first, within ~10 miles of Rivergrove. Listing isn't leaking, and distance isn't exposure.
- OREGON HEALTH AND SCIENCE UNIVERSITYBrownfields · 0.6 mi
- MERIDIAN PARK HOSPITALUnderground Storage Tanks · 0.6 mi
- LEGACY MERIDIAN PARK HOSPITALBrownfields · 0.6 mi
- WESTMARK INDUSTRIES INCORPORATEDBrownfields · 0.6 mi
- PIPER'S RUN APARTMENTSUnderground Storage Tanks · 0.7 mi
- AVIA GROUP INTERNATIONALUnderground Storage Tanks · 0.7 mi
- GUNCRETE CEMENT COMPANYUnderground Storage Tanks · 0.7 mi
- DAVID M KAO, MD PC, SKIN CANCER SURGERYBrownfields · 0.7 mi
- TUALATIN GAS & FOODUnderground Storage Tanks · 0.7 mi
- NORTHWEST NATURAL GAS CO TUALATIN SVCBrownfields · 0.7 mi
- TUALATIN SERVICE CENTERUnderground Storage Tanks · 0.7 mi
- ROOFLINE 322Brownfields · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Rivergrove'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 Rivergrove.
Sources Checked
within ~10 miles of Rivergrove
Severity Distribution
within ~10 miles of Rivergrove
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •TRI facilities report what they release. Check the wind — downwind beds catch more of it.
Check your specific parcel in Rivergrove
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 Rivergrove average
Your land is one point inside Rivergrove
Everything above resolves to Rivergrove as a whole — one PHZM band, read across 111 acres, with hard-freeze dates borrowed from Clackamas County’s record because no 30-year normal resolves at this city’s own centroid. 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 city 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 Rivergrove Average
Rivergrove Average
- ●USDA Zones 9a, averaged across Rivergrove
- ●One soil character for all of Rivergrove
- ●Frost dates read at Rivergrove's scale: Mar 25 to Nov 22
YOUR Parcel
- ✓Your exact zone, not Rivergrove's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Rivergrove
Pull a site-specific report for your exact address in Rivergrove, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Rivergrove averages can't show:
We read public map data around Rivergrove — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rivergrove average
How we know this about Rivergrove
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Clackamas County’s record, because none resolves here; 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 city grain anywhere on this page — there is no city-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 Rivergrove
When does frost risk typically end in Rivergrove?
The last hard freeze (28°F) in Rivergrove typically lands around Mar 25, 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 Apr 15.
When is the first frost in Rivergrove?
The first hard freeze (28°F) in Rivergrove typically arrives around Nov 22, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 8, so the watching starts about Oct 23 — about 242 days after the spring freeze cleared.
How long is the growing season in Rivergrove?
Measured between 28°F hard freezes, Rivergrove sees about 242 frost-free days — roughly Mar 25 through Nov 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 15 to Nov 8, about 207 days.
Is the soil safe to grow vegetables in Rivergrove?
The federal record around Rivergrove is a meaningful one — 2,630 documented sites, mostly Underground Storage Tanks entries (1,410), the nearest Brownfields record about 0.6 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Rivergrove?
From about Oct 23 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 22 (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 22. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Rivergrove's scale — its 9a band and its 242-day season. Your yard writes its own version of Rivergrove'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 Rivergrove’s own scale
6 of the readings below were taken at Rivergrove's own scale — the 111 acres it covers and 2,630 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Rivergrove's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 2,630 documented contamination sites on the federal record near Rivergrove, the closest Brownfields record about 0.6 miles out from the town centreFederal environmental registers
- Rivergrove's boundary and the 111 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~242-day seasonGrowable Ground crop-matching engine
- Rivergrove sits in the Willamette Valley — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- Lanternfly survey cells around Rivergrove checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — Rivergrove has no normal of its own, so its county's is the closest measured readfrom Clackamas County
- Soil character — no town-scale survey exists, so Rivergrove's 111 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 Rivergrove's 111 acreswhy one lot differs from the next →
- Which side of Rivergrove you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 111 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.6 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 Rivergrove-wide figureread your own land →