Midvale, Idaho, sits in USDA hardiness zone 6a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Expect cabbage, hazelnut, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Midvale, 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 Midvale 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 Midvale — soil, climate, flood, and parcel records. How we handle your address.
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Midvale — the short answer
Midvale, Idaho: USDA zone 6a, about 185 days between hard freezes, across 2K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~185
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 2K 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 Midvale's average, not your lot's — a low corner or a tree line moves it. Against Midvale's 185-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Midvale
Each reading below is measured for Midvale itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMidvale runs about 185 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
MeasuredMidvale 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 Midvale is in
Midvale sits in the Snake River Plain — EPA Level III, inside the wider North American Deserts. That is read at Midvale's own centroid rather than borrowed from Washington County.
What Grows in Midvale
Every plant below cleared Midvale's own zone 6a and its 185-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Midvale?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 17 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Midvale
Closest first, within ~10 miles of Midvale. Listing isn't leaking, and distance isn't exposure.
- 13N 03W 08CCC1Nitrate · 0.7 mi
- JOHN G PIPERUnderground Storage Tanks · 0.7 mi
- LEE WILLIAMS MEMORIAL AIRPORTUnderground Storage Tanks · 0.8 mi
- MIDVALE STATIONUnderground Storage Tanks · 0.8 mi
- 13N 03W 17DBB1Nitrate · 0.8 mi
- 13N 04W 13BAC1Nitrate · 1.4 mi
- Taylor CinnabarMining · 2.4 mi
- 14N 04W 36DDC1Nitrate · 2.8 mi
- 13N 03W 10CDA1Nitrate · 2.8 mi
- 14N 03W 19DDA1Nitrate · 4.7 mi
- Unnamed MineMining · 5.3 mi
- 12N 03W 01DCD1Nitrate · 6.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Midvale'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 Midvale.
Sources Checked
within ~10 miles of Midvale
Severity Distribution
within ~10 miles of Midvale
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Midvale, two things run higher than the national average within ~10 miles of Midvale — Nitrate (30 sites) and Mining (3 sites). 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.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Midvale
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 Midvale average
Your land is one point inside Midvale
Everything above resolves to Midvale as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Midvale Average
Midvale Average
- ●USDA Zones 6a, averaged across Midvale
- ●One soil character for all of Midvale
- ●Frost dates read at Midvale's scale: Apr 15 to Oct 17
YOUR Parcel
- ✓Your exact zone, not Midvale's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Midvale
Pull a site-specific report for your exact address in Midvale, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Midvale averages can't show:
We read public map data around Midvale — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Midvale average
How we know this about Midvale
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 Midvale’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 Midvale
When does frost risk typically end in Midvale?
The last hard freeze (28°F) in Midvale typically lands around Apr 15, 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 6.
When is the first frost in Midvale?
The first hard freeze (28°F) in Midvale typically arrives around Oct 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 3, so the watching starts about Sep 17 — about 185 days after the spring freeze cleared.
How long is the growing season in Midvale?
Measured between 28°F hard freezes, Midvale sees about 185 frost-free days — roughly Apr 15 through Oct 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 3, about 150 days.
Is the soil safe to grow vegetables in Midvale?
The federal record around Midvale shows 49 documented sites, mostly Nitrate entries (30), the nearest Nitrate record about 0.7 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 Midvale?
From about Sep 17 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 17 (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 17. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Midvale's scale — its 6a band and its 185-day season. Your yard writes its own version of Midvale'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 Midvale’s own scale
6 of the readings below were taken at Midvale's own scale — its own ~185-day season between 28°F freezes, the 1,645 acres it covers and 49 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Midvale's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Midvale's own 28°F hard-freeze dates, about Apr 15 and Oct 17 and the ~185-day span between themNOAA 1991–2020 Climate Normals
- 49 documented contamination sites on the federal record near Midvale, the closest Nitrate record about 0.7 miles out from the town centreFederal environmental registers
- Midvale's boundary and the 1,645 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~185-day seasonGrowable Ground crop-matching engine
- The ecoregion at Midvale's own centroid, the Snake River PlainUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Midvale's 1,645 acres read through its county's SSURGO summaryfrom Washington County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Washington 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 Washington County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Midvale's 1,645 acreswhy one lot differs from the next →
- Which side of Midvale you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,645 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.7 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 Midvale-wide figureread your own land →
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