Hartland Colony, Montana, sits in USDA hardiness zone 3b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Expect cabbage, cranberry, epazote, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Hartland Colony, 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 Hartland Colony 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 Hartland Colony — soil, climate, flood, and parcel records. How we handle your address.
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Hartland Colony — the short answer
Hartland Colony, Montana: USDA zone 3b, about 145 days between hard freezes, across 119 acres of town.
- USDA zone
- 3b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~145
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 119 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 3b is Hartland Colony's average, not your lot's — a low corner or a tree line moves it. Against Hartland Colony's 145-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Hartland Colony
Each reading below is measured for Hartland Colony itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHartland Colony runs about 145 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
MeasuredHartland Colony sits in USDA hardiness zone 3b.
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 Hartland Colony is in
Hartland Colony sits in the Northwestern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Hartland Colony's own centroid rather than borrowed from Blaine County.
What Grows in Hartland Colony
Every plant below cleared Hartland Colony's own zone 3b and its 145-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Hartland Colony?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 27 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
What's on the federal record near Hartland Colony
Closest first, within ~10 miles of Hartland Colony. Listing isn't leaking, and distance isn't exposure.
- 37N17E19BBCD01Nitrate · 4.8 mi
Measured from Hartland Colony'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 Hartland Colony.
Total Sites
2
within ~10 miles of Hartland Colony
Risk Level
Low
Highest-severity
2 nitrate monitoring sites
Severity Distribution
within ~10 miles of Hartland Colony
Know Before You Grow
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Hartland Colony
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 Hartland Colony average
Your land is one point inside Hartland Colony
Everything above resolves to Hartland Colony as a whole — one PHZM band and one 28°F frost record, read across 119 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 Hartland Colony Average
Hartland Colony Average
- ●USDA Zones 3b, averaged across Hartland Colony
- ●One soil character for all of Hartland Colony
- ●Frost dates read at Hartland Colony's scale: May 5 to Sep 27
YOUR Parcel
- ✓Your exact zone, not Hartland Colony's 3b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hartland Colony
Pull a site-specific report for your exact address in Hartland Colony, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hartland Colony averages can't show:
We read public map data around Hartland Colony — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hartland Colony average
How we know this about Hartland Colony
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 Hartland Colony’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 Hartland Colony
When does frost risk typically end in Hartland Colony?
The last hard freeze (28°F) in Hartland Colony typically lands around May 5, 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 26.
When is the first frost in Hartland Colony?
The first hard freeze (28°F) in Hartland Colony typically arrives around Sep 27, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 13, so the watching starts about Aug 28 — about 145 days after the spring freeze cleared.
How long is the growing season in Hartland Colony?
Measured between 28°F hard freezes, Hartland Colony sees about 145 frost-free days — roughly May 5 through Sep 27, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 26 to Sep 13, about 110 days.
Is the soil safe to grow vegetables in Hartland Colony?
The federal record around Hartland Colony is light — 2 documented sites across the 9 federal source types we checked, mostly Nitrate entries (2), the nearest Nitrate record about 4.8 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do gardeners stretch the season in Hartland Colony?
With about 145 frost-free days between hard freezes, Hartland Colony 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 173 to 201 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 5 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Hartland Colony's scale — its 3b band and its 145-day season. Your yard writes its own version of Hartland Colony'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 Hartland Colony’s own scale
6 of the readings below were taken at Hartland Colony's own scale — its own ~145-day season between 28°F freezes, the 119 acres it covers and 2 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hartland Colony's own USDA hardiness band, zones 3bUSDA PHZM 2023
- Hartland Colony's own 28°F hard-freeze dates, about May 5 and Sep 27 and the ~145-day span between themNOAA 1991–2020 Climate Normals
- 2 documented contamination sites on the federal record near Hartland Colony, the closest Nitrate record about 4.8 miles out from the town centreFederal environmental registers
- Hartland Colony's boundary and the 119 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 3b and a ~145-day seasonGrowable Ground crop-matching engine
- The ecoregion at Hartland Colony's own centroid, the Northwestern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hartland Colony's 119 acres read through its county's SSURGO summaryfrom Blaine County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Blaine 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 Blaine County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hartland Colony's 119 acreswhy one lot differs from the next →
- Which side of Hartland Colony you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 119 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 4.8 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 Hartland Colony-wide figureread your own land →
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