Bancroft, Idaho, sits in USDA hardiness zone 5a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Bancroft, 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 Bancroft 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 Bancroft — soil, climate, flood, and parcel records. How we handle your address.
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Bancroft — the short answer
Bancroft, Idaho: USDA zone 5a, about 138 days between hard freezes, across 390 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~138
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 390 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 5a is Bancroft's average, not your lot's — a low corner or a tree line moves it. Against Bancroft's 138-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Bancroft
Each reading below is measured for Bancroft itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBancroft runs about 138 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredBancroft sits in USDA hardiness zone 5a.
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 Bancroft is in
Bancroft sits in the Northern Basin and Range — EPA Level III, inside the wider North American Deserts. That is read at Bancroft's own centroid rather than borrowed from Caribou County.
What Grows in Bancroft
Every plant below cleared Bancroft's own zone 5a and its 138-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Bancroft?
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 Apr 12; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 25 — long-season crops need about 90 days of runway, quick greens only 30. When the window is tight, the fall moves are quick ones — baby greens, radishes, and garlic set for next season.
What's on the federal record near Bancroft
Closest first, within ~10 miles of Bancroft. Listing isn't leaking, and distance isn't exposure.
- MICK'S MARKETUnderground Storage Tanks · 600 ft
- CARIBOU COUNTY R&B SHOPUnderground Storage Tanks · 950 ft
- NORTH GEM SCHOOL # 149Underground Storage Tanks · 1100 ft
- GERALD TOLMANUnderground Storage Tanks · 1700 ft
- 08S 39E 22ACD1Nitrate · 1800 ft
- BANCROFT STATIONUnderground Storage Tanks · 2000 ft
- 08S 39E 22BAC1-DESTROYEDNitrate · 2100 ft
- 08S 39E 27DBBB1Nitrate · 1.4 mi
- 08S 39E 03ABC1Nitrate · 3.0 mi
- 08S 39E 01DAC1Nitrate · 3.1 mi
- Eliason & Sons, Inc.Underground Storage Tanks · 3.2 mi
- 08S 39E 01DAD1Nitrate · 3.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Bancroft'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 Bancroft.
Total Sites
76
within ~10 miles of Bancroft
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Bancroft
Severity Distribution
within ~10 miles of Bancroft
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Bancroft, Nitrate runs higher than the national average — 54 sites within ~10 miles of Bancroft. 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 Bancroft
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 Bancroft average
Your land is one point inside Bancroft
Everything above resolves to Bancroft as a whole — one PHZM band and one 28°F frost record, read across 390 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 city 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 Bancroft Average
Bancroft Average
- ●USDA Zones 5a, averaged across Bancroft
- ●One soil character for all of Bancroft
- ●Frost dates read at Bancroft's scale: May 10 to Sep 25
YOUR Parcel
- ✓Your exact zone, not Bancroft's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Bancroft
Pull a site-specific report for your exact address in Bancroft, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Bancroft averages can't show:
We read public map data around Bancroft — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Bancroft average
How we know this about Bancroft
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Bancroft’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 city grain anywhere on this page — there is no city-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 Bancroft
When does frost risk typically end in Bancroft?
The last hard freeze (28°F) in Bancroft typically lands around May 10, 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 31.
When is the first frost in Bancroft?
The first hard freeze (28°F) in Bancroft typically arrives around Sep 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 11, so the watching starts about Aug 26 — about 138 days after the spring freeze cleared.
How long is the growing season in Bancroft?
Measured between 28°F hard freezes, Bancroft sees about 138 frost-free days — roughly May 10 through Sep 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 31 to Sep 11, about 103 days.
Is the soil safe to grow vegetables in Bancroft?
The federal record around Bancroft shows 76 documented sites, mostly Nitrate entries (54), the nearest Underground Storage Tanks record about 0.1 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do gardeners stretch the season in Bancroft?
With about 138 frost-free days between hard freezes, Bancroft rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 166 to 194 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 10 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Bancroft's scale — its 5a band and its 138-day season. Your yard writes its own version of Bancroft'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 Bancroft’s own scale
6 of the readings below were taken at Bancroft's own scale — its own ~138-day season between 28°F freezes, the 390 acres it covers and 76 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Bancroft's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Bancroft's own 28°F hard-freeze dates, about May 10 and Sep 25 and the ~138-day span between themNOAA 1991–2020 Climate Normals
- 76 documented contamination sites on the federal record near Bancroft, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Bancroft's boundary and the 390 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~138-day seasonGrowable Ground crop-matching engine
- The ecoregion at Bancroft's own centroid, the Northern Basin and RangeUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Bancroft's 390 acres read through its county's SSURGO summaryfrom Caribou County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Caribou County
- The growing challenges every Idaho grower plans around — written at state scale, so they stay on the state guidefrom Idaho
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Caribou County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Bancroft's 390 acreswhy one lot differs from the next →
- Which side of Bancroft you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 390 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Bancroft-wide figureread your own land →