Altamont, Oregon, sits in USDA hardiness zone 6b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Well-matched crops include cabbage, blackberry, california poppy, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Altamont, 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 Altamont 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 Altamont — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Altamont — the short answer
Altamont, Oregon: USDA zone 6b, about 145 days between hard freezes, across 5K acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~145
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 5K 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 Altamont's average, not your lot's — a low corner or a tree line moves it. Against Altamont's 145-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Altamont
Each reading below is measured for Altamont itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAltamont 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
MeasuredAltamont 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 Altamont is in
Altamont sits in the Eastern Cascades Slopes and Foothills — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Altamont's own centroid rather than borrowed from Klamath County.
What Grows in Altamont
Every plant below cleared Altamont's own zone 6b and its 145-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in Altamont?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Apr 17; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 7 — 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 Altamont
Closest first, within ~10 miles of Altamont. Listing isn't leaking, and distance isn't exposure.
- HOMEDALE SERVICEUnderground Storage Tanks · 600 ft
- STURDI CRAFT INCUnderground Storage Tanks · 1700 ft
- STOREY, E EUnderground Storage Tanks · 0.6 mi
- CHEVRON USA INC #99685Underground Storage Tanks · 0.6 mi
- TESORO MOBIL #62528Underground Storage Tanks · 0.6 mi
- HOMEDALE SHELL & MARKETUnderground Storage Tanks · 0.6 mi
- BIG T TIRES, FORMERLYUnderground Storage Tanks · 0.6 mi
- ALBERTSONS NO 577Brownfields · 0.6 mi
- KLAMATH FALLS MOTEL MERCURYSuperfund · 0.6 mi
- TRUAX THIFTY #77Underground Storage Tanks · 0.7 mi
- LES SCHWAB TIRE CENTER OF OREGON INCUnderground Storage Tanks · 0.7 mi
- MADISON MARKETUnderground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Altamont'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 Altamont.
Sources Checked
within ~10 miles of Altamont
Severity Distribution
within ~10 miles of Altamont
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Altamont, two things run higher than the national average within ~10 miles of Altamont — Underground Storage Tanks (203 sites) and Superfund (4 sites). That's not a problem with your land — it's information about it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Altamont
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 Altamont average
Your land is one point inside Altamont
Everything above resolves to Altamont as a whole — one PHZM band and one 28°F frost record, read across 5K 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 Altamont Average
Altamont Average
- ●USDA Zones 6b, averaged across Altamont
- ●One soil character for all of Altamont
- ●Frost dates read at Altamont's scale: May 15 to Oct 7
YOUR Parcel
- ✓Your exact zone, not Altamont's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Altamont
Pull a site-specific report for your exact address in Altamont, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Altamont averages can't show:
We read public map data around Altamont — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Altamont average
How we know this about Altamont
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 Altamont’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 Altamont
When does frost risk typically end in Altamont?
The last hard freeze (28°F) in Altamont typically lands around May 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 Jun 5.
When is the first frost in Altamont?
The first hard freeze (28°F) in Altamont typically arrives around Oct 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 23, so the watching starts about Sep 7 — about 145 days after the spring freeze cleared.
How long is the growing season in Altamont?
Measured between 28°F hard freezes, Altamont sees about 145 frost-free days — roughly May 15 through Oct 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 5 to Sep 23, about 110 days.
Is the soil safe to grow vegetables in Altamont?
The federal record around Altamont is a meaningful one — 277 documented sites, mostly Underground Storage Tanks entries (203), the nearest Underground Storage Tanks record about 0.1 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do gardeners stretch the season in Altamont?
With about 145 frost-free days between hard freezes, Altamont 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 15 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Altamont's scale — its 6b band and its 145-day season. Your yard writes its own version of Altamont'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 Altamont’s own scale
6 of the readings below were taken at Altamont's own scale — its own ~145-day season between 28°F freezes, the 5,158 acres it covers and 277 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Altamont's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Altamont's own 28°F hard-freeze dates, about May 15 and Oct 7 and the ~145-day span between themNOAA 1991–2020 Climate Normals
- 277 documented contamination sites on the federal record near Altamont, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Altamont's boundary and the 5,158 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~145-day seasonGrowable Ground crop-matching engine
- The ecoregion at Altamont's own centroid, the Eastern Cascades Slopes and FoothillsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Altamont's 5,158 acres read through its county's SSURGO summaryfrom Klamath County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Klamath County
- The growing challenges every Oregon grower plans around — written at state scale, so they stay on the state guidefrom Oregon
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Klamath County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Altamont's 5,158 acreswhy one lot differs from the next →
- Which side of Altamont you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 5,158 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Altamont-wide figureread your own land →
More in Oregon
Growing region
Nearby growing guides