Preston, Idaho, sits in USDA hardiness zone 6a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Growers here do well with cabbage, blackberry, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Preston, 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 Preston 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 Preston — soil, climate, flood, and parcel records. How we handle your address.
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Preston — the short answer
Preston, Idaho: USDA zone 6a, about 166 days between hard freezes, across 4K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~166
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 4K 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 6a is Preston's average, not your lot's — a low corner or a tree line moves it. Against Preston's 166-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Preston
Each reading below is measured for Preston itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredPreston runs about 166 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
MeasuredPreston sits in USDA hardiness zone 6a.
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 Preston is in
Preston sits in the Central Basin and Range — EPA Level III, inside the wider North American Deserts. That is read at Preston's own centroid, and it is not what its county reads: Franklin County is mostly Northern Basin and Range. The wider page above you is answering a different question about different ground.
What Grows in Preston
Every plant below cleared Preston's own zone 6a and its 166-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Preston?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 11 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Preston
Closest first, within ~10 miles of Preston. Listing isn't leaking, and distance isn't exposure.
- Legacy PlazaUnderground Storage Tanks · 1100 ft
- Kelly's LLCUnderground Storage Tanks · 1100 ft
- Kelly's ExxonUnderground Storage Tanks · 1100 ft
- PRESTON GAR (16)Underground Storage Tanks · 1300 ft
- FRANKLIN COUNTY EXTENSION OFFICEUnderground Storage Tanks · 1400 ft
- PALMER MOTORUnderground Storage Tanks · 1400 ft
- WEST MOTOR CO INCUnderground Storage Tanks · 1500 ft
- PRESTON CLEANERSBrownfields · 1700 ft
- FRANKLIN COUNTY ROAD DEPTUnderground Storage Tanks · 1800 ft
- FRANKLIN COUNTY MEDICAL CENTERUnderground Storage Tanks · 2000 ft
- ROUNDS INSURANCEUnderground Storage Tanks · 2100 ft
- PRESTON GAR (15)Underground Storage Tanks · 2200 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Preston'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 Preston.
Total Sites
106
within ~10 miles of Preston
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Preston
Severity Distribution
within ~10 miles of Preston
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Preston, Nitrate runs higher than the national average — 54 sites within ~10 miles of Preston. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 Preston
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 Preston average
Your land is one point inside Preston
Everything above resolves to Preston as a whole — one PHZM band and one 28°F frost record, read across 4K 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 Preston Average
Preston Average
- ●USDA Zones 6a, averaged across Preston
- ●One soil character for all of Preston
- ●Frost dates read at Preston's scale: Apr 28 to Oct 11
YOUR Parcel
- ✓Your exact zone, not Preston's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Preston
Pull a site-specific report for your exact address in Preston, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Preston averages can't show:
We read public map data around Preston — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Preston average
How we know this about Preston
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 Preston’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 Preston
When does frost risk typically end in Preston?
The last hard freeze (28°F) in Preston typically lands around Apr 28, 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 19.
When is the first frost in Preston?
The first hard freeze (28°F) in Preston typically arrives around Oct 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 27, so the watching starts about Sep 11 — about 166 days after the spring freeze cleared.
How long is the growing season in Preston?
Measured between 28°F hard freezes, Preston sees about 166 frost-free days — roughly Apr 28 through Oct 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Sep 27, about 131 days.
Is the soil safe to grow vegetables in Preston?
The federal record around Preston shows 106 documented sites, mostly Nitrate entries (54), the nearest Underground Storage Tanks record about 0.2 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 I protect my plants from frost in Preston?
From about Sep 11 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 Oct 11 (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 Oct 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Preston's scale — its 6a band and its 166-day season. Your yard writes its own version of Preston'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 Preston’s own scale
6 of the readings below were taken at Preston's own scale — its own ~166-day season between 28°F freezes, the 4,370 acres it covers and 106 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Preston's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Preston's own 28°F hard-freeze dates, about Apr 28 and Oct 11 and the ~166-day span between themNOAA 1991–2020 Climate Normals
- 106 documented contamination sites on the federal record near Preston, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Preston's boundary and the 4,370 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~166-day seasonGrowable Ground crop-matching engine
- Preston sits in the Central Basin and Range — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Preston's 4,370 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 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 Franklin County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Preston's 4,370 acreswhy one lot differs from the next →
- Which side of Preston you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,370 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 Preston-wide figureread your own land →
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