Heron, Montana, sits in USDA hardiness zone 6b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
A short list that earns its place here — cabbage, blackberry, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Heron, 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 Heron 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 Heron — soil, climate, flood, and parcel records. How we handle your address.
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Heron — the short answer
Heron, Montana: USDA zone 6b, about 170 days between hard freezes, across 3K acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~170
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 3K 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 6b is Heron's average, not your lot's — a low corner or a tree line moves it. Against Heron's 170-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Heron
Each reading below is measured for Heron itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHeron runs about 170 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
MeasuredHeron sits in USDA hardiness zone 6b.
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 Heron is in
Heron sits in the Northern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Heron's own centroid rather than borrowed from Sanders County.
What Grows in Heron
Every plant below cleared Heron's own zone 6b and its 170-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Heron?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 13 — 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's on the federal record near Heron
Closest first, within ~10 miles of Heron. Listing isn't leaking, and distance isn't exposure.
- SANDERS COUNTY HERON MAINTENANCEUnderground Storage Tanks · 2400 ft
- HERON SCHOOL 4502636Underground Storage Tanks · 1.0 mi
- HERON SCHOOL 4512828Underground Storage Tanks · 1.0 mi
- THE HERON STORE AND CAF?ëUnderground Storage Tanks · 1.0 mi
- 27N34W35DABA01Nitrate · 1.2 mi
- RyanMining · 2.4 mi
- Frederick and Wind GroupMining · 2.7 mi
- Red Fir ClaimsMining · 2.9 mi
- Amazon PropertyMining · 3.2 mi
- Gopher Hole MineMining · 3.4 mi
- UlleyMining · 3.6 mi
- CABINET GORGE DAMBrownfields · 3.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Heron'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 Heron.
Sources Checked
within ~10 miles of Heron
Severity Distribution
within ~10 miles of Heron
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Heron, Mining runs higher than the national average — 40 sites within ~10 miles of Heron. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
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 soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Heron
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 Heron average
Your land is one point inside Heron
Everything above resolves to Heron as a whole — one PHZM band and one 28°F frost record, read across 3K 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 Heron Average
Heron Average
- ●USDA Zones 6b, averaged across Heron
- ●One soil character for all of Heron
- ●Frost dates read at Heron's scale: Apr 26 to Oct 13
YOUR Parcel
- ✓Your exact zone, not Heron's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Heron
Pull a site-specific report for your exact address in Heron, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Heron averages can't show:
We read public map data around Heron — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Heron average
How we know this about Heron
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 Heron’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 Heron
When does frost risk typically end in Heron?
The last hard freeze (28°F) in Heron typically lands around Apr 26, 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 17.
When is the first frost in Heron?
The first hard freeze (28°F) in Heron typically arrives around Oct 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 29, so the watching starts about Sep 13 — about 170 days after the spring freeze cleared.
How long is the growing season in Heron?
Measured between 28°F hard freezes, Heron sees about 170 frost-free days — roughly Apr 26 through Oct 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 17 to Sep 29, about 135 days.
Is the soil safe to grow vegetables in Heron?
The federal record around Heron runs heavier than most — 62 documented sites, mostly Mining entries (40), the nearest Underground Storage Tanks record about 0.5 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Heron?
From about Sep 13 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 13 (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 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Heron's scale — its 6b band and its 170-day season. Your yard writes its own version of Heron'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 Heron’s own scale
6 of the readings below were taken at Heron's own scale — its own ~170-day season between 28°F freezes, the 3,260 acres it covers and 62 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Heron's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Heron's own 28°F hard-freeze dates, about Apr 26 and Oct 13 and the ~170-day span between themNOAA 1991–2020 Climate Normals
- 62 documented contamination sites on the federal record near Heron, the closest Underground Storage Tanks record about 0.5 miles out from the town centreFederal environmental registers
- Heron's boundary and the 3,260 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~170-day seasonGrowable Ground crop-matching engine
- The ecoregion at Heron's own centroid, the Northern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Heron's 3,260 acres read through its county's SSURGO summaryfrom Sanders County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Sanders County
- The growing challenges every Montana grower plans around — written at state scale, so they stay on the state guidefrom Montana
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Sanders County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Heron's 3,260 acreswhy one lot differs from the next →
- Which side of Heron you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,260 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.5 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 Heron-wide figureread your own land →
More in Montana
Wider growing context
What grows across MontanaHeron sits outside our named growing regions, so Montana as a whole is its closest context here.
Nearby growing guides