Richfield, California, 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.
Reliable performers under these conditions include tomato, artichoke, fig, and california poppy; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Richfield, 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 Richfield 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 Richfield — soil, climate, flood, and parcel records. How we handle your address.
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Richfield — the short answer
Richfield, California: USDA zone 9a, about 325 days between hard freezes, across 350 acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 22
- Tehama County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 13
- Tehama County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~325
- Tehama County normal — NOAA 1991–2020, nearest to this town
- Town area
- 350 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 Tehama County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Richfield's average, not your lot's — a low corner or a tree line moves it. Against Richfield's 325-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Richfield
Each reading below is measured for Richfield itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsRichfield runs about 325 days between hard freezes (read from Tehama County, the closest normal to Richfield) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredRichfield 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 Richfield is in
Richfield sits in the Central California Valley — EPA Level III, inside the wider Mediterranean California. That is read at Richfield's own centroid, and it is not what its county reads: Tehama County is mostly Central California Foothills and Coastal Mountains. The wider page above you is answering a different question about different ground.
What Grows in Richfield
Plants matched to Richfield's USDA zones 9a, ordered by how much hardiness margin each has here — the ones with room to spare at both ends of this town's band lead. Each links to its full growing profile.
Is it too late to plant in Richfield?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 13 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
What's on the federal record near Richfield
Closest first, within ~10 miles of Richfield. Listing isn't leaking, and distance isn't exposure.
- NORTHLAND CEDAR INCBrownfields · 400 ft
- WALBERG INCBrownfields · 1200 ft
- 025N003W35L001MNitrate · 1200 ft
- 025N003W35F001MNitrate · 2500 ft
- SIERRA PACIFIC INDUSTRIESBrownfields · 0.7 mi
- ABA ENERGY CORP-VBC #1 WELLBrownfields · 0.9 mi
- 025N003W36L001MNitrate · 0.9 mi
- 025N003W36C001MNitrate · 1.3 mi
- 024N003W10L001MNitrate · 2.0 mi
- JASON ABEL CONSTRUCTION INCBrownfields · 2.2 mi
- THE PALERMO RANCHBrownfields · 2.2 mi
- CORNING VALEROBrownfields · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Richfield'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 Richfield.
Total Sites
308
within ~10 miles of Richfield
Risk Level
Elevated
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Richfield
Severity Distribution
within ~10 miles of Richfield
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Richfield, Nitrate runs higher than the national average — 182 sites within ~10 miles of Richfield. That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Richfield
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 Richfield average
Your land is one point inside Richfield
Everything above resolves to Richfield as a whole — one PHZM band, read across 350 acres, with hard-freeze dates borrowed from Tehama County’s record because no 30-year normal resolves at this town’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 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 Richfield Average
Richfield Average
- ●USDA Zones 9a, averaged across Richfield
- ●One soil character for all of Richfield
- ●Frost dates read at Richfield's scale: Jan 22 to Dec 13
YOUR Parcel
- ✓Your exact zone, not Richfield's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Richfield
Pull a site-specific report for your exact address in Richfield, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Richfield averages can't show:
We read public map data around Richfield — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Richfield average
How we know this about Richfield
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 Tehama 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 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 Richfield
When does frost risk typically end in Richfield?
The last hard freeze (28°F) in Richfield typically lands around Jan 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 Feb 12.
When is the first frost in Richfield?
The first hard freeze (28°F) in Richfield typically arrives around Dec 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 29, so the watching starts about Nov 13 — about 325 days after the spring freeze cleared.
How long is the growing season in Richfield?
Measured between 28°F hard freezes, Richfield sees about 325 frost-free days — roughly Jan 22 through Dec 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 12 to Nov 29, about 290 days.
Is the soil safe to grow vegetables in Richfield?
The federal record around Richfield is a meaningful one — 308 documented sites, mostly Nitrate entries (182), the nearest Brownfields 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 Richfield?
From about Nov 13 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 Dec 13 (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 Dec 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Richfield's scale — its 9a band and its 325-day season. Your yard writes its own version of Richfield'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 Richfield’s own scale
4 of the readings below were taken at Richfield's own scale — the 350 acres it covers and 308 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Richfield's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 308 documented contamination sites on the federal record near Richfield, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Richfield's boundary and the 350 acres inside itUS Census TIGER/Line 2025
- Richfield sits in the Central California Valley — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Richfield has no normal of its own, so its county's is the closest measured readfrom Tehama County
- Soil character — no town-scale survey exists, so Richfield's 350 acres read through its county's SSURGO summaryfrom Tehama County
- The candidate plant list — California's curated set, filtered to this zone band and re-ordered by how much margin each has herefrom California
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Tehama County
- The growing challenges every California grower plans around — written at state scale, so they stay on the state guidefrom California
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Tehama County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Richfield's 350 acreswhy one lot differs from the next →
- Which side of Richfield you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 350 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Richfield-wide figureread your own land →