Sula, Montana, sits in USDA hardiness zone 5a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor cabbage, cranberry, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Sula, 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 Sula 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 Sula — soil, climate, flood, and parcel records. How we handle your address.
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Sula — the short answer
Sula, Montana: USDA zone 5a, about 122 days between hard freezes, across 2K acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~122
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town 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 5a is Sula's average, not your lot's — a low corner or a tree line moves it. Against Sula's 122-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sula
Each reading below is measured for Sula itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSula runs about 122 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
MeasuredSula 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 Sula is in
Sula sits in the Idaho Batholith — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Sula's own centroid rather than borrowed from Ravalli County.
What Grows in Sula
Every plant below cleared Sula's own zone 5a and its 122-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Sula?
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 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 15 — 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 Sula
Closest first, within ~10 miles of Sula. Listing isn't leaking, and distance isn't exposure.
- 01N19W10CBBB01Nitrate · 1500 ft
- SULA COUNTRY STORE LLCUnderground Storage Tanks · 1.4 mi
- Unnamed Be OccMining · 2.3 mi
- Broken File ProspectMining · 2.5 mi
- TRAVELERS VILLAGEUnderground Storage Tanks · 3.7 mi
- BITTERROOT N F SULA RANGER STATUnderground Storage Tanks · 5.0 mi
- EAST FORK GUARD STATIONUnderground Storage Tanks · 5.0 mi
- Lucky StrikeMining · 5.7 mi
- Art L. WildeyMining · 8.7 mi
- Logger Claims GroupMining · 9.1 mi
- Logger Bugle Ridge GroupMining · 9.5 mi
- 02N20W18DBAC01Nitrate · 9.8 mi
1 more site is on the record inside the same radius. See them on the map
Measured from Sula'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 Sula.
Severity Distribution
within ~10 miles of Sula
Highest-Severity Sites
Know Before You Grow
- •Mine waste leaches heavy metals. Test for lead, arsenic and cadmium before growing food here.
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Sula
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 Sula average
Your land is one point inside Sula
Everything above resolves to Sula 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 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 Sula Average
Sula Average
- ●USDA Zones 5a, averaged across Sula
- ●One soil character for all of Sula
- ●Frost dates read at Sula's scale: May 16 to Sep 15
YOUR Parcel
- ✓Your exact zone, not Sula's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sula
Pull a site-specific report for your exact address in Sula, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sula averages can't show:
We read public map data around Sula — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sula average
How we know this about Sula
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 Sula’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 Sula
When does frost risk typically end in Sula?
The last hard freeze (28°F) in Sula typically lands around May 16, 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 Jun 6.
When is the first frost in Sula?
The first hard freeze (28°F) in Sula typically arrives around Sep 15, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 1, so the watching starts about Aug 16 — about 122 days after the spring freeze cleared.
How long is the growing season in Sula?
Measured between 28°F hard freezes, Sula sees about 122 frost-free days — roughly May 16 through Sep 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 6 to Sep 1, about 87 days.
Is the soil safe to grow vegetables in Sula?
The federal record around Sula is light — 16 documented sites across the 9 federal source types we checked, mostly Mining entries (7), the nearest Nitrate record about 0.3 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 Sula?
With about 122 frost-free days between hard freezes, Sula 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 150 to 178 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 16 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Sula's scale — its 5a band and its 122-day season. Your yard writes its own version of Sula'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 Sula’s own scale
6 of the readings below were taken at Sula's own scale — its own ~122-day season between 28°F freezes, the 2,094 acres it covers and 16 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Sula's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Sula's own 28°F hard-freeze dates, about May 16 and Sep 15 and the ~122-day span between themNOAA 1991–2020 Climate Normals
- 16 documented contamination sites on the federal record near Sula, the closest Nitrate record about 0.3 miles out from the town centreFederal environmental registers
- Sula's boundary and the 2,094 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~122-day seasonGrowable Ground crop-matching engine
- The ecoregion at Sula's own centroid, the Idaho BatholithUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Sula's 2,094 acres read through its county's SSURGO summaryfrom Ravalli County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Ravalli 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 Ravalli County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sula's 2,094 acreswhy one lot differs from the next →
- Which side of Sula you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,094 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.3 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 Sula-wide figureread your own land →
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