Joppa, Illinois, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Well-matched crops include cabbage, hazelnut, california poppy, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Joppa, 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 Joppa 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 Joppa — soil, climate, flood, and parcel records. How we handle your address.
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Joppa — the short answer
Joppa, Illinois: USDA zone 7a, about 239 days between hard freezes, across 311 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~239
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 311 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 7a is Joppa's average, not your lot's — a low corner or a tree line moves it. Against Joppa's 239-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Joppa
Each reading below is measured for Joppa itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredJoppa runs about 239 days between hard freezes — 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
MeasuredJoppa sits in USDA hardiness zone 7a.
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 Joppa is in
Joppa sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Joppa's own centroid rather than borrowed from Massac County.
What Grows in Joppa
Every plant below cleared Joppa's own zone 7a and its 239-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Joppa?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 14 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
What's on the federal record near Joppa
Closest first, within ~10 miles of Joppa. Listing isn't leaking, and distance isn't exposure.
- Joppa Compressor StationUnderground Storage Tanks · 1300 ft
- Joppa Village OfUnderground Storage Tanks · 1300 ft
- Roy Peck StandardUnderground Storage Tanks · 1300 ft
- JT's Burgers & MoreUnderground Storage Tanks · 1800 ft
- ELECTRIC ENERGY INCToxics Release Inventory · 0.6 mi
- ELECTRIC ENERGY INCBrownfields · 0.6 mi
- REPUBLIC CREOSOTING COSuperfund · 0.6 mi
- 15S 3E-23.1h1Nitrate · 0.7 mi
- Electric Energy, Inc.Underground Storage Tanks · 1.0 mi
- TRUNKLINE GAS COBrownfields · 1.4 mi
- Commercial Transport IncUnderground Storage Tanks · 1.7 mi
- HOLCIM (US) INCBrownfields · 1.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Joppa'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 Joppa.
Sources Checked
within ~10 miles of Joppa
Severity Distribution
within ~10 miles of Joppa
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Joppa, two things run higher than the national average within ~10 miles of Joppa — Superfund (5 sites) and PFAS (3 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Superfund: Superfund sites represent the most severe contamination in the federal system.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Joppa
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 Joppa average
Your land is one point inside Joppa
Everything above resolves to Joppa as a whole — one PHZM band and one 28°F frost record, read across 311 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 Joppa Average
Joppa Average
- ●USDA Zones 7a, averaged across Joppa
- ●One soil character for all of Joppa
- ●Frost dates read at Joppa's scale: Mar 20 to Nov 14
YOUR Parcel
- ✓Your exact zone, not Joppa's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Joppa
Pull a site-specific report for your exact address in Joppa, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Joppa averages can't show:
We read public map data around Joppa — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Joppa average
How we know this about Joppa
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 Joppa’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 Joppa
When does frost risk typically end in Joppa?
The last hard freeze (28°F) in Joppa typically lands around Mar 20, 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 10.
When is the first frost in Joppa?
The first hard freeze (28°F) in Joppa typically arrives around Nov 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 31, so the watching starts about Oct 15 — about 239 days after the spring freeze cleared.
How long is the growing season in Joppa?
Measured between 28°F hard freezes, Joppa sees about 239 frost-free days — roughly Mar 20 through Nov 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 10 to Oct 31, about 204 days.
Is the soil safe to grow vegetables in Joppa?
The federal record around Joppa is a meaningful one — 159 documented sites, mostly Underground Storage Tanks entries (80), the nearest Underground Storage Tanks record about 0.2 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 Joppa?
From about Oct 15 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 14 (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 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Joppa's scale — its 7a band and its 239-day season. Your yard writes its own version of Joppa'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 Joppa’s own scale
6 of the readings below were taken at Joppa's own scale — its own ~239-day season between 28°F freezes, the 311 acres it covers and 159 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Joppa's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Joppa's own 28°F hard-freeze dates, about Mar 20 and Nov 14 and the ~239-day span between themNOAA 1991–2020 Climate Normals
- 159 documented contamination sites on the federal record near Joppa, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Joppa's boundary and the 311 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~239-day seasonGrowable Ground crop-matching engine
- The ecoregion at Joppa's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Joppa's 311 acres read through its county's SSURGO summaryfrom Massac County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Massac County
- The growing challenges every Illinois grower plans around — written at state scale, so they stay on the state guidefrom Illinois
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Massac County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Joppa's 311 acreswhy one lot differs from the next →
- Which side of Joppa you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 311 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Joppa-wide figureread your own land →