Lucas County, in Iowa, sits in USDA hardiness zone 5b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Well-matched crops include cabbage, cranberry, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Lucas County holds more than one microclimate.
Soils and elevations shift across Lucas County, so your frost dates and drainage aren't the county average. 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 Lucas County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Lucas County — the short answer
Lucas County, Iowa: USDA zone 5b, about 197 days between hard freezes, across 276K acres.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 11
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 25
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~197
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 276K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 5b is Lucas County's average, not your lot's — a low corner or a tree line moves it. Against Lucas County's 197-day season, see what your own ground reads.
Heat in Lucas County
Across a year, Lucas County accumulates about 2,943 growing degree days above 50°F, about 199 more than the middle Iowa county — ahead of 67 of Iowa’s 99 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Lucas County
Across Lucas County, the ground is predominantly Alfisols, where Gara, Armstrong, and Pershing are the most extensive named soil series. The soil is generally somewhat poorly drained with a silty clay loam surface. Topsoil pH runs about 6.0–6.5, slightly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Somewhat poorly drained
Prime farmland
9%
Hydric soils
20%
Soil still varies lot by lot — soil types explained.
How the ground varies across Lucas County
The USDA soil survey maps 51% of Lucas County as somewhat poorly drained — but another 48% drains differently: 23% poorly drained, 22% well drained.
Gara is the most extensive named soil at 14% of mapped acres, then Armstrong (10%) and Pershing (9%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Lucas County
Each reading below is measured for Lucas County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Lucas County are somewhat poorly drained, in hydrologic group D — ground that sheds water slowly.
Beds can stay saturated for days after heavy rain, and the roots of most vegetables, berries, and fruit trees suffocate or rot in soil that never drains.
Raised beds or mounded rows lift roots above the wet zone; choose water-tolerant crops for the lowest spots.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Lucas County runs about pH 6.0–6.5, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredLucas County runs about 197 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredLucas County sits in USDA hardiness zone 5b.
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 Lucas County is in
Lucas County sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Lucas County
We scored all 1,086 plants against Lucas County's own USDA zone 5b and its own 197-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Iowa profile.
Is it too late to plant in Lucas County?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 25 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
What gets applied to farmland in Lucas County
USGS estimates 50,562 lb of Glyphosate on Lucas County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (26,980 lb) and Acetochlor (18,928 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Lucas County — and how to grow with it.
We checked the federal record across Lucas County — 203 documented sites across 6 of the 9 source types we track.
The most significant on record: 3 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Lucas County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Lucas County
Closest first, across Lucas County. Listing isn't leaking, and distance isn't exposure.
- HY-VEE PERISHABLE DIST CENTERBrownfields · 1500 ft
- JOHNSON MACHINE WORKS INCBrownfields · 2500 ft
- JOINT CITY/COUNTY FUELUnderground Storage Tanks · 0.6 mi
- SOUTH CENTRAL COOPUnderground Storage Tanks · 0.7 mi
- HY-VEEUnderground Storage Tanks · 0.8 mi
- HY-VEE DISTRIBUTION CENTERUnderground Storage Tanks · 0.8 mi
- HY-VEE DISTRIBUTION CENTERBrownfields · 0.9 mi
- CHARITON COMMUNITY SCHOOL DISTRICTUnderground Storage Tanks · 1.0 mi
- LUCAS COUNTY SHOPUnderground Storage Tanks · 1.0 mi
- CHARITON STREET DEPTUnderground Storage Tanks · 1.0 mi
- CHARITON IOWA CITY OFBrownfields · 1.0 mi
- NORTH LIFT STATIONUnderground Storage Tanks · 1.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Lucas County'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 Lucas County.
Total Sites
203
across Lucas County
Risk Level
Elevated
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
across Lucas County
Severity Distribution
across Lucas County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Lucas County, Nitrate runs higher than the national average — 134 sites across Lucas County. That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Lucas County
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 Lucas County average
Your land is one point inside Lucas County
Everything above resolves to Lucas County as a whole — one PHZM band and one county frost record, read across 276K 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 county 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 county average.
Your Lot vs the Lucas County Average
Lucas County Average
- ●USDA Zones 5b, averaged across Lucas County
- ●One soil character for all of Lucas County
- ●Frost dates read at Lucas County's scale: Apr 11 to Oct 25
YOUR Parcel
- ✓Your exact zone, not Lucas County's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Lucas County
Pull a site-specific report for your exact address in Lucas County, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Lucas County averages can't show:
We read public map data around Lucas County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Lucas County average
How we know this about Lucas County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Lucas County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Lucas County
When does frost risk typically end in Lucas County?
The last hard freeze (28°F) in Lucas County typically lands around Apr 11, 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 May 2.
How long is the growing season in Lucas County?
Measured between 28°F hard freezes, Lucas County sees about 197 frost-free days — roughly Apr 11 through Oct 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 2 to Oct 11, about 162 days.
Is the soil safe to grow vegetables in Lucas County?
The federal record around Lucas County is a meaningful one — 203 documented sites, mostly Nitrate entries (134), the nearest Brownfields record about 0.3 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.
Everything above is measured at Lucas County's scale — its 5b band and its 197-day season. Your yard writes its own version of Lucas County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Iowa's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Lucas County’s own scale
8 of the readings below were taken at Lucas County's own scale — its own ~197-day span between 28°F freezes, the 3 most extensive soil series mapped here and 203 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Lucas County's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Lucas County's own 28°F hard-freeze dates and its ~197-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Lucas CountyUSDA NRCS SSURGO
- 203 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 0.3 miles outFederal environmental registers
- Lucas County's boundary and the 275,635 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~197-day seasonGrowable Ground crop-matching engine
- Lucas County sitting wholly inside the Central Irregular PlainsUS EPA Level III Ecoregions
- Which agricultural compounds go onto Lucas County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Iowa grower plans around — written at state scale, so they stay on the state guidefrom Iowa
What this page can’t tell you
- How the season shifts across Lucas County — the ~197 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Lucas County's 275,635 acreswhy one lot differs from the next →
- Which of those 203 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Lucas Countyread your own land →