Whitmore, California, sits in USDA hardiness zone 9a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
These conditions suit artichoke, fig, california poppy, and cabbage — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Whitmore, 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 Whitmore 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 Whitmore — soil, climate, flood, and parcel records. How we handle your address.
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Whitmore — the short answer
Whitmore, California: USDA zone 9a, about 286 days between hard freezes, across 4K acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Dec 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~286
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 4K 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 9a is Whitmore's average, not your lot's — a low corner or a tree line moves it. Against Whitmore's 286-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Whitmore
Each reading below is measured for Whitmore itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredWhitmore runs about 286 days between hard freezes — 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
MeasuredWhitmore 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 Whitmore is in
Whitmore sits in the Cascades — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Whitmore's own centroid rather than borrowed from Shasta County.
What Grows in Whitmore
Every plant below cleared Whitmore's own zone 9a and its 286-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Whitmore?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 5 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
What's on the federal record near Whitmore
Closest first, within ~10 miles of Whitmore. Listing isn't leaking, and distance isn't exposure.
- 032N001E18E001MNitrate · 1.7 mi
- Clover CreekMining · 3.9 mi
- Clover Creek MineMining · 4.3 mi
- Clover Creek Copper LeaseMining · 5.9 mi
- 031N001W25D001MNitrate · 6.5 mi
- Oak Run Country StoreUnderground Storage Tanks · 6.9 mi
- ALLTEL TUOLUMNE TELEPHONE COBrownfields · 7.1 mi
- TEEN RESCUE INC RVCABrownfields · 7.5 mi
- 031N001E31K001MNitrate · 8.1 mi
- Maruti ShingletownUnderground Storage Tanks · 8.6 mi
- Reed's MarketUnderground Storage Tanks · 8.6 mi
- REEDS MARKETBrownfields · 8.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Whitmore'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 Whitmore.
Sources Checked
within ~10 miles of Whitmore
Severity Distribution
within ~10 miles of Whitmore
Highest-Severity Sites
Know Before You Grow
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •Mine waste leaches heavy metals. Test for lead, arsenic and cadmium before growing food here.
Check your specific parcel in Whitmore
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 Whitmore average
Your land is one point inside Whitmore
Everything above resolves to Whitmore as a whole — one PHZM band and one 28°F frost record, read across 4K 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 Whitmore Average
Whitmore Average
- ●USDA Zones 9a, averaged across Whitmore
- ●One soil character for all of Whitmore
- ●Frost dates read at Whitmore's scale: Feb 22 to Dec 5
YOUR Parcel
- ✓Your exact zone, not Whitmore's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Whitmore
Pull a site-specific report for your exact address in Whitmore, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Whitmore averages can't show:
We read public map data around Whitmore — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Whitmore average
How we know this about Whitmore
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 Whitmore’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 Whitmore
When does frost risk typically end in Whitmore?
The last hard freeze (28°F) in Whitmore typically lands around Feb 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 Mar 15.
When is the first frost in Whitmore?
The first hard freeze (28°F) in Whitmore typically arrives around Dec 5, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 21, so the watching starts about Nov 5 — about 286 days after the spring freeze cleared.
How long is the growing season in Whitmore?
Measured between 28°F hard freezes, Whitmore sees about 286 frost-free days — roughly Feb 22 through Dec 5, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 15 to Nov 21, about 251 days.
Is the soil safe to grow vegetables in Whitmore?
The federal record around Whitmore shows 23 documented sites, mostly Nitrate entries (8), the nearest Nitrate record about 1.7 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 Whitmore?
From about Nov 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 Dec 5 (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 5. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Whitmore's scale — its 9a band and its 286-day season. Your yard writes its own version of Whitmore'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 Whitmore’s own scale
6 of the readings below were taken at Whitmore's own scale — its own ~286-day season between 28°F freezes, the 4,179 acres it covers and 23 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Whitmore's own USDA hardiness band, zones 9aUSDA PHZM 2023
- Whitmore's own 28°F hard-freeze dates, about Feb 22 and Dec 5 and the ~286-day span between themNOAA 1991–2020 Climate Normals
- 23 documented contamination sites on the federal record near Whitmore, the closest Nitrate record about 1.7 miles out from the town centreFederal environmental registers
- Whitmore's boundary and the 4,179 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~286-day seasonGrowable Ground crop-matching engine
- The ecoregion at Whitmore's own centroid, the CascadesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Whitmore's 4,179 acres read through its county's SSURGO summaryfrom Shasta County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Shasta 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 Shasta County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Whitmore's 4,179 acreswhy one lot differs from the next →
- Which side of Whitmore you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,179 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 1.7 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 Whitmore-wide figureread your own land →
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