Morro Bay, California, sits in USDA hardiness zone 10a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
These conditions suit avocado, meyer lemon, tomato, and artichoke — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Morro Bay, 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 Morro Bay 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 Morro Bay — soil, climate, flood, and parcel records. How we handle your address.
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Morro Bay — the short answer
Morro Bay, California: USDA zone 10a, about 228 days between hard freezes, across 3K acres of city.
- USDA zone
- 10a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 1
- San Luis Obispo County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 15
- San Luis Obispo County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~228
- San Luis Obispo County normal — NOAA 1991–2020, nearest to this town
- City area
- 3K 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 Luis Obispo County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 10a is Morro Bay's average, not your lot's — a low corner or a tree line moves it. Against Morro Bay's 228-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Morro Bay
Each reading below is measured for Morro Bay itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsMorro Bay runs about 228 days between hard freezes (read from San Luis Obispo County, the closest normal to Morro Bay) — 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
MeasuredMorro Bay sits in USDA hardiness zone 10a.
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
What Grows in Morro Bay
Plants matched to Morro Bay's USDA zones 10a, 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 Morro Bay?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 15 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
What's on the federal record near Morro Bay
Closest first, within ~10 miles of Morro Bay. Listing isn't leaking, and distance isn't exposure.
- USCG MOORING MORRO BAYBrownfields · 0.7 mi
- DYNEGY MORRO BAY POWER PLANTBrownfields · 0.8 mi
- CITY OF MORRO BAY HARBOR YARDBrownfields · 0.8 mi
- CENTRAL COAST FUEL & ICEUnderground Storage Tanks · 0.8 mi
- DEGARIMORE'S CENTRAL COAST MARINE & FUEL LLCBrownfields · 0.8 mi
- BEAR METAL KUSTOMS INCBrownfields · 0.9 mi
- THE BAY FOUNDATION OF MORRO BAY DBA MORRO BAY ESTUARY PROGRAMBrownfields · 0.9 mi
- EDDIE'S CUSTOM CARSBrownfields · 0.9 mi
- ASSOCIATED PACIFIC CONSTRUCTORS INCBrownfields · 1.0 mi
- HANSON FAMILY PARTNERSHIPBrownfields · 1.0 mi
- MORRO BAY-CAYUCOS SANITARY DISTRICT PERMANENT HHW COLLECTION FACILITYBrownfields · 1.0 mi
- TROSS MOBILE AUTO & RLV SERVICESBrownfields · 1.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Morro Bay'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 Morro Bay.
Total Sites
260
within ~10 miles of Morro Bay
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Morro Bay
Severity Distribution
within ~10 miles of Morro Bay
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Morro Bay, two things run higher than the national average within ~10 miles of Morro Bay — Mining (107 sites) and PFAS (4 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Morro Bay
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 Morro Bay average
Your land is one point inside Morro Bay
Everything above resolves to Morro Bay as a whole — one PHZM band, read across 3K acres, with hard-freeze dates borrowed from San Luis Obispo 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 Morro Bay Average
Morro Bay Average
- ●USDA Zones 10a, averaged across Morro Bay
- ●One soil character for all of Morro Bay
- ●Frost dates read at Morro Bay's scale: Apr 1 to Nov 15
YOUR Parcel
- ✓Your exact zone, not Morro Bay's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Morro Bay
Pull a site-specific report for your exact address in Morro Bay, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Morro Bay averages can't show:
We read public map data around Morro Bay — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Morro Bay average
How we know this about Morro Bay
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 Luis Obispo 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 Morro Bay
When does frost risk typically end in Morro Bay?
The last hard freeze (28°F) in Morro Bay typically lands around Apr 1, 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 22.
When is the first frost in Morro Bay?
The first hard freeze (28°F) in Morro Bay typically arrives around Nov 15, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 1, so the watching starts about Oct 16 — about 228 days after the spring freeze cleared.
How long is the growing season in Morro Bay?
Measured between 28°F hard freezes, Morro Bay sees about 228 frost-free days — roughly Apr 1 through Nov 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 22 to Nov 1, about 193 days.
Is the soil safe to grow vegetables in Morro Bay?
The federal record around Morro Bay is a meaningful one — 260 documented sites, mostly Brownfields entries (131), the nearest Brownfields record about 0.7 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 Morro Bay?
From about Oct 16 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 15 (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 15. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Morro Bay's scale — its 10a band and its 228-day season. Your yard writes its own version of Morro Bay'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 Morro Bay’s own scale
3 of the readings below were taken at Morro Bay's own scale — the 3,416 acres it covers and 260 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Morro Bay's own USDA hardiness band, zones 10aUSDA PHZM 2023
- 260 documented contamination sites on the federal record near Morro Bay, the closest Brownfields record about 0.7 miles out from the town centreFederal environmental registers
- Morro Bay's boundary and the 3,416 acres inside itUS Census TIGER/Line 2025
Inherited from a wider read
- The 28°F hard-freeze dates — Morro Bay has no normal of its own, so its county's is the closest measured readfrom San Luis Obispo County
- Soil character — no town-scale survey exists, so Morro Bay's 3,416 acres read through its county's SSURGO summaryfrom San Luis Obispo 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 Luis Obispo 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 Luis Obispo County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Morro Bay's 3,416 acreswhy one lot differs from the next →
- Which side of Morro Bay you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,416 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.7 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 Morro Bay-wide figureread your own land →