Royalton, Illinois, sits in USDA hardiness zone 7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Crops well matched to these conditions include cabbage, hazelnut, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Royalton, 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 Royalton 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 Royalton — soil, climate, flood, and parcel records. How we handle your address.
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Royalton — the short answer
Royalton, Illinois: USDA zone 7a, about 226 days between hard freezes, across 714 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 6
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~226
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 714 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 Royalton's average, not your lot's — a low corner or a tree line moves it. Against Royalton's 226-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Royalton
Each reading below is measured for Royalton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRoyalton runs about 226 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
MeasuredRoyalton 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 Royalton is in
Royalton sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Royalton's own centroid rather than borrowed from Franklin County.
What Grows in Royalton
Every plant below cleared Royalton's own zone 7a and its 226-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Royalton?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 6 — 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 Royalton
Closest first, within ~10 miles of Royalton. Listing isn't leaking, and distance isn't exposure.
- DOLLAR GENERAL STORE 8772Brownfields · 350 ft
- Caseys General StoreUnderground Storage Tanks · 700 ft
- Royalton Village OfUnderground Storage Tanks · 750 ft
- Holliday Mini Marts, Inc. d/b/a Royalton Mini MartUnderground Storage Tanks · 750 ft
- Sunco StationUnderground Storage Tanks · 1.9 mi
- Prudent James EUnderground Storage Tanks · 2.8 mi
- Brown TedUnderground Storage Tanks · 2.9 mi
- ZIEGLER RAYALTON HIGH SCHOOLBrownfields · 2.9 mi
- T&T RECYCLING INCBrownfields · 2.9 mi
- Casey's General Stores #2388Underground Storage Tanks · 3.1 mi
- Ziegler Food & GasUnderground Storage Tanks · 3.2 mi
- Tom NotoUnderground Storage Tanks · 3.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Royalton'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 Royalton.
Total Sites
196
within ~10 miles of Royalton
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Royalton
Severity Distribution
within ~10 miles of Royalton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Royalton, Underground Storage Tanks runs higher than the national average — 128 sites within ~10 miles of Royalton. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Royalton
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 Royalton average
Your land is one point inside Royalton
Everything above resolves to Royalton as a whole — one PHZM band and one 28°F frost record, read across 714 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 Royalton Average
Royalton Average
- ●USDA Zones 7a, averaged across Royalton
- ●One soil character for all of Royalton
- ●Frost dates read at Royalton's scale: Mar 25 to Nov 6
YOUR Parcel
- ✓Your exact zone, not Royalton's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Royalton
Pull a site-specific report for your exact address in Royalton, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Royalton averages can't show:
We read public map data around Royalton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Royalton average
How we know this about Royalton
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 Royalton’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 Royalton
When does frost risk typically end in Royalton?
The last hard freeze (28°F) in Royalton typically lands around Mar 25, 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 15.
When is the first frost in Royalton?
The first hard freeze (28°F) in Royalton typically arrives around Nov 6, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 23, so the watching starts about Oct 7 — about 226 days after the spring freeze cleared.
How long is the growing season in Royalton?
Measured between 28°F hard freezes, Royalton sees about 226 frost-free days — roughly Mar 25 through Nov 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 15 to Oct 23, about 191 days.
Is the soil safe to grow vegetables in Royalton?
The federal record around Royalton is a meaningful one — 196 documented sites, mostly Underground Storage Tanks entries (128), the nearest Brownfields record under a tenth of a mile 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 Royalton?
From about Oct 7 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 6 (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 6. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Royalton's scale — its 7a band and its 226-day season. Your yard writes its own version of Royalton'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 Royalton’s own scale
6 of the readings below were taken at Royalton's own scale — its own ~226-day season between 28°F freezes, the 714 acres it covers and 196 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Royalton's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Royalton's own 28°F hard-freeze dates, about Mar 25 and Nov 6 and the ~226-day span between themNOAA 1991–2020 Climate Normals
- 196 documented contamination sites on the federal record near Royalton, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Royalton's boundary and the 714 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~226-day seasonGrowable Ground crop-matching engine
- The ecoregion at Royalton'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 Royalton's 714 acres read through its county's SSURGO summaryfrom Franklin County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Franklin 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 Franklin County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Royalton's 714 acreswhy one lot differs from the next →
- Which side of Royalton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 714 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 Royalton-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisRoyalton sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides