South Monrovia Island, California, sits in USDA hardiness zone 10a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
These conditions suit artichoke, meyer lemon, california poppy, and cabbage — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in South Monrovia Island, 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 South Monrovia Island 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 South Monrovia Island — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
South Monrovia Island — the short answer
South Monrovia Island, California: USDA zone 10a, no 28°F killing freeze on record — the season is year-round, across 351 acres of town.
- USDA zone
- 10a
- USDA PHZM 2023
- Killing freeze
- None on record
- NOAA RCC ACIS 1991–2020, this town’s own record
- Town area
- 351 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. The year-round finding is measured — a 30-year record with no 28°F killing freeze in it — never inferred from missing dates.
Hardiness Zone Range
Zone 10a is South Monrovia Island's average, not your lot's — a low corner or a tree line moves it. Against South Monrovia Island's no killing freeze on record, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in South Monrovia Island
Each reading below is measured for South Monrovia Island itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Winter hardiness
MeasuredSouth Monrovia Island 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
The kind of country South Monrovia Island is in
South Monrovia Island sits in the Southern California/Northern Baja Coast — EPA Level III, inside the wider Mediterranean California. That is read at South Monrovia Island's own centroid rather than borrowed from Los Angeles County.
What Grows in South Monrovia Island
Every plant below cleared South Monrovia Island's own zone 10a. Each card opens that plant's California profile. How we score.
What's on the federal record near South Monrovia Island
Closest first, within ~10 miles of South Monrovia Island. Listing isn't leaking, and distance isn't exposure.
- CRCD 069Brownfields · 1200 ft
- CRCD 058Brownfields · 1300 ft
- SAN GABRIEL VALLEY (AREA 1)Superfund · 1400 ft
- FAYE ANGELESBrownfields · 1500 ft
- GEM CITY AUTO BODY FRAMEBrownfields · 2000 ft
- TOTAL PERFORMANCE ENTBrownfields · 2000 ft
- KRUSE & SON INCBrownfields · 2000 ft
- ARA'S AUTO SALES & SERVICEBrownfields · 2000 ft
- WEISS PROPERTIES, INC.Brownfields · 2000 ft
- EMERGENCY RESPONSEBrownfields · 2100 ft
- MIHM INC DBA EMERGENCY RESPONSE CRIME SCENE CLEANINGBrownfields · 2100 ft
- ADVANCE MARINE AND DEVELOPMENTBrownfields · 2100 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from South Monrovia Island'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 South Monrovia Island.
Total Sites
7,824
within ~10 miles of South Monrovia Island
Risk Level
High
Highest-severity
38 Superfund sites
Sources Checked
within ~10 miles of South Monrovia Island
Severity Distribution
within ~10 miles of South Monrovia Island
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around South Monrovia Island, Brownfields runs higher than the national average — 6,898 sites within ~10 miles of South Monrovia Island. That's not a problem with your land — it's information about 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 South Monrovia Island
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 South Monrovia Island average
Your land is one point inside South Monrovia Island
Everything above resolves to South Monrovia Island as a whole — one PHZM band and one 28°F frost record, read across 351 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 South Monrovia Island Average
South Monrovia Island Average
- ●USDA Zones 10a, averaged across South Monrovia Island
- ●One soil character for all of South Monrovia Island
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not South Monrovia Island's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in South Monrovia Island
Pull a site-specific report for your exact address in South Monrovia Island, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that South Monrovia Island averages can't show:
We read public map data around South Monrovia Island — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the South Monrovia Island average
How we know this about South Monrovia Island
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, with the labelled statewide window where none resolves; 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 South Monrovia Island
Is it too late to plant in South Monrovia Island?
No — South Monrovia Island has no 28°F killing freeze in the 30-year station record, so the growing season is year-round and there is no last-frost date to wait for. Planting is paced by rainfall, heat and daylength instead of by frost: start heat-lovers any month, and time cool-season crops (lettuce, brassicas, peas) for the cooler, wetter half of the year or for higher ground. Succession sowing every few weeks works all year, so the limit is what you can keep watered and harvested, not the calendar.
When does frost risk typically end in South Monrovia Island?
It doesn't — South Monrovia Island records no 28°F killing freeze at all across the 1991–2020 station record, so there is no spring frost date to plant after. Cold still matters with elevation: the higher you garden, the cooler the nights, and a few tropical crops sulk below about 60°F even where they never freeze.
How long is the growing season in South Monrovia Island?
Year-round — the 1991–2020 station record for South Monrovia Island contains no 28°F killing freeze, so there is no season to measure between freezes. What paces planting instead is heat, rainfall and daylength: the hottest, wettest stretch is the hard part for cool-season crops, not winter. Elevation is the one real exception — the higher you garden, the colder the nights get.
Is the soil safe to grow vegetables in South Monrovia Island?
The federal record around South Monrovia Island runs heavier than most — 7,824 documented sites, mostly Brownfields entries (6,898), the nearest Brownfields record about 0.2 miles 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.
Everything above is measured at South Monrovia Island's scale — its 10a band and its no killing freeze on record. Your yard writes its own version of South Monrovia Island'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 South Monrovia Island’s own scale
6 of the readings below were taken at South Monrovia Island's own scale — the 351 acres it covers and 7,824 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- South Monrovia Island's own USDA hardiness band, zones 10aUSDA PHZM 2023
- No 28°F killing freeze in the 30-year station record covering South Monrovia Island — a year-round growing seasonNOAA Regional Climate Centers ACIS, 1991-2020
- 7,824 documented contamination sites on the federal record near South Monrovia Island, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- South Monrovia Island's boundary and the 351 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear South Monrovia Island's hardiness zoneGrowable Ground crop-matching engine
- The ecoregion at South Monrovia Island's own centroid, the Southern California/Northern Baja CoastUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so South Monrovia Island's 351 acres read through its county's SSURGO summaryfrom Los Angeles County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Los Angeles 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 Los Angeles County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among South Monrovia Island's 351 acreswhy one lot differs from the next →
- Which side of South Monrovia Island you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 351 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.2 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 South Monrovia Island-wide figureread your own land →