Carlsbad, California, sits in USDA hardiness zone 10b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Reliable performers under these conditions include avocado, meyer lemon, tomato, and artichoke; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Carlsbad, 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 Carlsbad 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 Carlsbad — soil, climate, flood, and parcel records. How we handle your address.
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Carlsbad — the short answer
Carlsbad, California: USDA zone 10b, about 311 days between hard freezes, across 24K acres of city.
- USDA zone
- 10b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 3
- San Diego County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 11
- San Diego County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~311
- San Diego County normal — NOAA 1991–2020, nearest to this town
- City area
- 24K 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 San Diego County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 10b is Carlsbad's average, not your lot's — a low corner or a tree line moves it. Against Carlsbad's 311-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Carlsbad
Each reading below is measured for Carlsbad itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsCarlsbad runs about 311 days between hard freezes (read from San Diego County, the closest normal to Carlsbad) — 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
MeasuredCarlsbad sits in USDA hardiness zone 10b.
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 Carlsbad is in
Carlsbad sits in the Southern California/Northern Baja Coast — EPA Level III, inside the wider Mediterranean California. That is read at Carlsbad's own centroid rather than borrowed from San Diego County.
What Grows in Carlsbad
Plants matched to Carlsbad's USDA zones 10b, 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 Carlsbad?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Jan 6; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 11 — 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.
Documented around Carlsbad
Spotted lanternfly documented 6 miles from Carlsbad, first recorded 2022. What to watch for.
What's on the federal record near Carlsbad
Closest first, within ~10 miles of Carlsbad. Listing isn't leaking, and distance isn't exposure.
- MACHINE VISION PRODUCTS INCBrownfields · 450 ft
- PRATT & WHITNEY, CMC CENTER OF EXCELLENCEBrownfields · 450 ft
- COBRA GULF WEST COAST COMPOSITES DIVBrownfields · 500 ft
- COBRA GULF WEST COAST COMPOSITES DIVToxics Release Inventory · 500 ft
- CARLSBAD TECHNOLOGY INCBrownfields · 500 ft
- BIOSPYDER TECHNOLOGIESBrownfields · 700 ft
- MARDX DIAGNOSTICS INCBrownfields · 800 ft
- ANCHOR AUDIO INCBrownfields · 1000 ft
- SHIMADZU SCIENTIFIC INSTRUMENTS SCA REGIONBrownfields · 1100 ft
- CALLAWAY GOLF COBrownfields · 1100 ft
- CALLAWAY GOLF COToxics Release Inventory · 1100 ft
- CARLSBAD TECHNOLOGYBrownfields · 1100 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Carlsbad'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 Carlsbad.
Total Sites
3,546
within ~10 miles of Carlsbad
Risk Level
High
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Carlsbad
Severity Distribution
within ~10 miles of Carlsbad
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Carlsbad, Brownfields runs higher than the national average — 3,012 sites within ~10 miles of Carlsbad. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
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 Carlsbad
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 Carlsbad average
Your land is one point inside Carlsbad
Everything above resolves to Carlsbad as a whole — one PHZM band, read across 24K acres, with hard-freeze dates borrowed from San Diego 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 Carlsbad Average
Carlsbad Average
- ●USDA Zones 10b, averaged across Carlsbad
- ●One soil character for all of Carlsbad
- ●Frost dates read at Carlsbad's scale: Feb 3 to Dec 11
YOUR Parcel
- ✓Your exact zone, not Carlsbad's 10b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Carlsbad
Pull a site-specific report for your exact address in Carlsbad, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Carlsbad averages can't show:
We read public map data around Carlsbad — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Carlsbad average
How we know this about Carlsbad
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 San Diego 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 Carlsbad
When does frost risk typically end in Carlsbad?
The last hard freeze (28°F) in Carlsbad typically lands around Feb 3, 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 24.
When is the first frost in Carlsbad?
The first hard freeze (28°F) in Carlsbad typically arrives around Dec 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 27, so the watching starts about Nov 11 — about 311 days after the spring freeze cleared.
How long is the growing season in Carlsbad?
Measured between 28°F hard freezes, Carlsbad sees about 311 frost-free days — roughly Feb 3 through Dec 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 24 to Nov 27, about 276 days.
Is the soil safe to grow vegetables in Carlsbad?
The federal record around Carlsbad runs heavier than most — 3,546 documented sites, mostly Brownfields entries (3,012), the nearest Brownfields record under a tenth of a mile out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Carlsbad?
From about Nov 11 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Carlsbad's scale — its 10b band and its 311-day season. Your yard writes its own version of Carlsbad'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 Carlsbad’s own scale
5 of the readings below were taken at Carlsbad's own scale — the 24,200 acres it covers and 3,546 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Carlsbad's own USDA hardiness band, zones 10bUSDA PHZM 2023
- 3,546 documented contamination sites on the federal record near Carlsbad, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Carlsbad's boundary and the 24,200 acres inside itUS Census TIGER/Line 2025
- The ecoregion at Carlsbad's own centroid, the Southern California/Northern Baja CoastUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Carlsbadlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — Carlsbad has no normal of its own, so its county's is the closest measured readfrom San Diego County
- Soil character — no town-scale survey exists, so Carlsbad's 24,200 acres read through its county's SSURGO summaryfrom San Diego 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 San Diego 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 San Diego County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Carlsbad's 24,200 acreswhy one lot differs from the next →
- Which side of Carlsbad you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 24,200 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 Carlsbad-wide figureread your own land →
More in California
Wider growing context
What grows across CaliforniaCarlsbad sits outside our named growing regions, so California as a whole is its closest context here.
Nearby growing guides