Bay St. Louis, Mississippi, sits in USDA hardiness zones 9a-10b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
On paper, pecan, okra, muscadine grape, and magnolia all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Bay St. Louis, 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 Bay St. Louis lot. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
9a-10b
Last Frost (state avg.)
Feb 28 - Mar 30
First Frost (state avg.)
Oct 25 - Nov 20
City Area
9K acres
Hardiness Zone Range
Growing Season
Zone maps are averages across Bay St. Louis. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil varies lot by lot — soil types explained.
What Grows in Bay St. Louis
Plants matched to Bay St. Louis's USDA zones 9a-10b — each links to its full growing profile.
Growing Challenges in Mississippi
What an experienced grower plans around here — each one has a move.
Extreme summer heat and humidity
Run the garden on the generous spring and fall windows — and let summer belong to okra, peas, and sweet potatoes.
Heavy alluvial clay in the Delta region
Delta clay is rich but slow to drain — raised rows get roots above the wet while keeping that fertility in reach.
Frequent severe storms and flooding
Site beds on the high ground, mound the rows, and keep water moving — drainage planning is storm insurance.
For cultivar selection, pest pressure, and planting-time guidance specific to Mississippi, the Mississippi State University Extension Service is the authoritative local source.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Sources Checked
within ~10 miles of Bay St. Louis
Severity Distribution
within ~10 miles of Bay St. Louis
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Bay St. Louis, two things run higher than the national average — PFAS (5 sites) and Superfund (5 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Bay St. Louis
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Bay St. Louis Average
- ●USDA Zones 9a-10b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Bay St. Louis
Pull a site-specific report for your exact address in Bay St. Louis, Mississippi — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Bay St. Louis, Mississippi
- USDA Hardiness Zones: 9a-10b (USDA PHZM 2023)
- Last Spring Frost (state avg.): Feb 28 - Mar 30 (NOAA 30-Year Climate Normals)
- First Fall Frost (state avg.): Oct 25 - Nov 20 (NOAA 30-Year Climate Normals)
- Land Area: 9K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.
Frequently Asked Questions
What hardiness zone is Bay St. Louis, Mississippi?
Bay St. Louis sits in USDA hardiness zones 9a-10b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
When does frost risk typically end in Bay St. Louis?
Bay St. Louis follows Mississippi's statewide frost window: last spring frost around Feb 28 - Mar 30 and first fall frost around Oct 25 - Nov 20, per NOAA 30-year climate normals (1991–2020). Frost dates shift with elevation and local microclimate, so watch your own site's cold pockets.
What vegetables grow in Bay St. Louis?
Bay St. Louis's zones 9a-10b support a wide range — strong performers include Pecan, Okra, Muscadine Grape, Magnolia, and Sweet Potato. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Bay St. Louis, really?
Officially, Bay St. Louis sits in USDA zones 9a-10b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Bay St. Louis?
The federal record around Bay St. Louis runs heavier than most — 251 documented sites — 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 Bay St. Louis?
As the season closes around Mississippi's first fall frost near Oct 25 - Nov 20 (NOAA 30-year climate normals (1991–2020)), a few moves buy time: cover tender plants with floating row cover or an old sheet on still, clear nights, water the soil the afternoon before a freeze so it holds warmth overnight, and harvest frost-tender crops like tomatoes, peppers, and basil before the first hard night. Hardy greens and root crops shrug off light frost and often sweeten after it, so leave them in.
Everything on this page is a Bay St. Louis average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
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