Hermiston, Oregon, sits in USDA hardiness zone 7b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor cabbage, prickly pear, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Hermiston, 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 Hermiston 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 Hermiston — soil, climate, flood, and parcel records. How we handle your address.
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Hermiston — the short answer
Hermiston, Oregon: USDA zone 7b, about 224 days between hard freezes, across 5K acres of city.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~224
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 5K 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 Hermiston's average, not your lot's — a low corner or a tree line moves it. Against Hermiston's 224-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Hermiston
Each reading below is measured for Hermiston itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHermiston runs about 224 days between hard freezes — 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
MeasuredHermiston 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 Hermiston is in
Hermiston sits in the Columbia Plateau — EPA Level III, inside the wider North American Deserts. That is read at Hermiston's own centroid rather than borrowed from Umatilla County.
What Grows in Hermiston
Every plant below cleared Hermiston's own zone 7b and its 224-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in Hermiston?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 1 — 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.
What's on the federal record near Hermiston
Closest first, within ~10 miles of Hermiston. Listing isn't leaking, and distance isn't exposure.
- ONE STOP # 9Underground Storage Tanks · 300 ft
- JOANNE KOSMOSUnderground Storage Tanks · 1400 ft
- ROHRMAN MOTOR COMPANYUnderground Storage Tanks · 1600 ft
- PACIFIC POWER & LIGHTUnderground Storage Tanks · 1600 ft
- HERMISTON HIGH SCHOOLBrownfields · 1700 ft
- OR STATE HWY 5-12 HERMISTONUnderground Storage Tanks · 2200 ft
- HERMISTON, CITY OF - PUBLIC SAFETY CTRUnderground Storage Tanks · 2300 ft
- HERMISTON IRRIGATION DISTRICTUnderground Storage Tanks · 2400 ft
- DORITY USED CARSUnderground Storage Tanks · 2400 ft
- QWEST CORPORATION dba CENTURYLINK QC (R0Underground Storage Tanks · 2500 ft
- FORMER REHER'S SERVICEUnderground Storage Tanks · 2600 ft
- PENDLETON GRAIN GROWERS INCUnderground Storage Tanks · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Hermiston'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 Hermiston.
Sources Checked
within ~10 miles of Hermiston
Severity Distribution
within ~10 miles of Hermiston
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hermiston, two things run higher than the national average within ~10 miles of Hermiston — CAFO (5 sites) and Superfund (6 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Hermiston
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 Hermiston average
Your land is one point inside Hermiston
Everything above resolves to Hermiston as a whole — one PHZM band and one 28°F frost record, read across 5K 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 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 Hermiston Average
Hermiston Average
- ●USDA Zones 7b, averaged across Hermiston
- ●One soil character for all of Hermiston
- ●Frost dates read at Hermiston's scale: Mar 22 to Nov 1
YOUR Parcel
- ✓Your exact zone, not Hermiston's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hermiston
Pull a site-specific report for your exact address in Hermiston, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hermiston averages can't show:
We read public map data around Hermiston — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hermiston average
How we know this about Hermiston
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 Hermiston’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 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 Hermiston
When does frost risk typically end in Hermiston?
The last hard freeze (28°F) in Hermiston typically lands around Mar 22, 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 12.
When is the first frost in Hermiston?
The first hard freeze (28°F) in Hermiston typically arrives around Nov 1, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 18, so the watching starts about Oct 2 — about 224 days after the spring freeze cleared.
How long is the growing season in Hermiston?
Measured between 28°F hard freezes, Hermiston sees about 224 frost-free days — roughly Mar 22 through Nov 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 12 to Oct 18, about 189 days.
Is the soil safe to grow vegetables in Hermiston?
The federal record around Hermiston is a meaningful one — 239 documented sites, mostly Underground Storage Tanks entries (146), the nearest Underground Storage Tanks record under a tenth of a mile 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 Hermiston?
From about Oct 2 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 1 (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 1. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Hermiston's scale — its 7b band and its 224-day season. Your yard writes its own version of Hermiston'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 Hermiston’s own scale
6 of the readings below were taken at Hermiston's own scale — its own ~224-day season between 28°F freezes, the 5,413 acres it covers and 239 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hermiston's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Hermiston's own 28°F hard-freeze dates, about Mar 22 and Nov 1 and the ~224-day span between themNOAA 1991–2020 Climate Normals
- 239 documented contamination sites on the federal record near Hermiston, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Hermiston's boundary and the 5,413 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~224-day seasonGrowable Ground crop-matching engine
- The ecoregion at Hermiston's own centroid, the Columbia PlateauUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hermiston's 5,413 acres read through its county's SSURGO summaryfrom Umatilla County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Umatilla 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 Umatilla County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hermiston's 5,413 acreswhy one lot differs from the next →
- Which side of Hermiston you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 5,413 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Hermiston-wide figureread your own land →