Isleton, California, sits in USDA hardiness zone 9b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Expect okra, meyer lemon, california poppy, and artichoke to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Isleton, 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 Isleton 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 Isleton — soil, climate, flood, and parcel records. How we handle your address.
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Isleton — the short answer
Isleton, California: USDA zone 9b, about 324 days between hard freezes, across 282 acres of city.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 22
- Sacramento County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 12
- Sacramento County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~324
- Sacramento County normal — NOAA 1991–2020, nearest to this town
- City area
- 282 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 Sacramento County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Isleton's average, not your lot's — a low corner or a tree line moves it. Against Isleton's 324-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Isleton
Each reading below is measured for Isleton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsIsleton runs about 324 days between hard freezes (read from Sacramento County, the closest normal to Isleton) — 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
MeasuredIsleton sits in USDA hardiness zone 9b.
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 Isleton is in
Isleton sits in the Central California Valley — EPA Level III, inside the wider Mediterranean California. That is read at Isleton's own centroid rather than borrowed from Sacramento County.
What Grows in Isleton
Every plant below cleared Isleton's own zone 9b and its 324-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Isleton?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. 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 12 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
What's on the federal record near Isleton
Closest first, within ~10 miles of Isleton. Listing isn't leaking, and distance isn't exposure.
- SMUD STATION ABrownfields · 650 ft
- 004N003E26H001MNitrate · 700 ft
- RIVER DELTA UNIFIED SCHOOL DISTRICT, ISLETON SCHOOLBrownfields · 850 ft
- CALIFORNIA AMERICAN WATER ISLETON TREATMENT PLANTBrownfields · 2100 ft
- RAMOS OIL COBrownfields · 0.7 mi
- H DENIS VAN DE MAELEBrownfields · 1.1 mi
- SILVA FARMSBrownfields · 1.2 mi
- PUMP HOUSE RANCHES INCBrownfields · 1.8 mi
- PETERSON FARMSBrownfields · 1.9 mi
- AMENT MARINE SERVICEBrownfields · 1.9 mi
- STEVE DINELLI FARMSBrownfields · 2.0 mi
- VIEIRAS RESORT INCBrownfields · 2.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Isleton'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 Isleton.
Sources Checked
within ~10 miles of Isleton
Severity Distribution
within ~10 miles of Isleton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Isleton, Brownfields runs higher than the national average — 213 sites within ~10 miles of Isleton. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Isleton
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 Isleton average
Your land is one point inside Isleton
Everything above resolves to Isleton as a whole — one PHZM band, read across 282 acres, with hard-freeze dates borrowed from Sacramento 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 Isleton Average
Isleton Average
- ●USDA Zones 9b, averaged across Isleton
- ●One soil character for all of Isleton
- ●Frost dates read at Isleton's scale: Jan 22 to Dec 12
YOUR Parcel
- ✓Your exact zone, not Isleton's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Isleton
Pull a site-specific report for your exact address in Isleton, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Isleton averages can't show:
We read public map data around Isleton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Isleton average
How we know this about Isleton
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 Sacramento 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 Isleton
When does frost risk typically end in Isleton?
The last hard freeze (28°F) in Isleton 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 Isleton?
The first hard freeze (28°F) in Isleton typically arrives around Dec 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 28, so the watching starts about Nov 12 — about 324 days after the spring freeze cleared.
How long is the growing season in Isleton?
Measured between 28°F hard freezes, Isleton sees about 324 frost-free days — roughly Jan 22 through Dec 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 12 to Nov 28, about 289 days.
Is the soil safe to grow vegetables in Isleton?
The federal record around Isleton is a meaningful one — 247 documented sites, mostly Brownfields entries (213), the nearest Brownfields record about 0.1 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 Isleton?
From about Nov 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Isleton's scale — its 9b band and its 324-day season. Your yard writes its own version of Isleton'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 Isleton’s own scale
5 of the readings below were taken at Isleton's own scale — the 282 acres it covers and 247 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Isleton's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 247 documented contamination sites on the federal record near Isleton, the closest Brownfields record about 0.1 miles out from the town centreFederal environmental registers
- Isleton's boundary and the 282 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~324-day seasonGrowable Ground crop-matching engine
- The ecoregion at Isleton's own centroid, the Central California ValleyUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Isleton has no normal of its own, so its county's is the closest measured readfrom Sacramento County
- Soil character — no town-scale survey exists, so Isleton's 282 acres read through its county's SSURGO summaryfrom Sacramento County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Sacramento 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 Sacramento County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Isleton's 282 acreswhy one lot differs from the next →
- Which side of Isleton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 282 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.1 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 Isleton-wide figureread your own land →