Rosalia, Washington, 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.
Among the crops suited to this profile: cabbage, blackberry, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Rosalia, 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 Rosalia 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 Rosalia — soil, climate, flood, and parcel records. How we handle your address.
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Rosalia — the short answer
Rosalia, Washington: USDA zone 6b, about 175 days between hard freezes, across 402 acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~175
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 402 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 Rosalia's average, not your lot's — a low corner or a tree line moves it. Against Rosalia's 175-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Rosalia
Each reading below is measured for Rosalia itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRosalia runs about 175 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
MeasuredRosalia 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 Rosalia is in
Rosalia sits in the Columbia Plateau — EPA Level III, inside the wider North American Deserts. That is read at Rosalia's own centroid rather than borrowed from Whitman County.
What Grows in Rosalia
Every plant below cleared Rosalia's own zone 6b and its 175-day season. Each card opens that plant's Washington profile. How we score.
Is it too late to plant in Rosalia?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 14 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Rosalia
Closest first, within ~10 miles of Rosalia. Listing isn't leaking, and distance isn't exposure.
- ROSALIA CENTRAL OFFICE (4610-B01)Underground Storage Tanks · 1600 ft
- JENSEN TEXACOUnderground Storage Tanks · 1600 ft
- THE TIRE SHOP ROSALIA CHEVRONUnderground Storage Tanks · 1700 ft
- ROSALIA SCHOOL DISTRICT 320Underground Storage Tanks · 2600 ft
- 10N/43E-10R01 SU001Nitrate · 2600 ft
- W F WILHELM & SON INCUnderground Storage Tanks · 0.7 mi
- RANDOLPH E MATTAUSCHUnderground Storage Tanks · 0.7 mi
- MCGREGOR CO ROSALIAUnderground Storage Tanks · 0.7 mi
- RDS #320 - TRANSPORTATION DEPTUnderground Storage Tanks · 0.9 mi
- WA DOT ROSALIA STORAGE SITEUnderground Storage Tanks · 1.5 mi
- WESTERN FARM SERVICE INC ROSALIAUnderground Storage Tanks · 2.0 mi
- PGT COMPRESSOR STATION 6 ROSALIAUnderground Storage Tanks · 3.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Rosalia'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 Rosalia.
Sources Checked
within ~10 miles of Rosalia
Severity Distribution
within ~10 miles of Rosalia
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rosalia, Underground Storage Tanks runs higher than the national average — 38 sites within ~10 miles of Rosalia. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Rosalia
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 Rosalia average
Your land is one point inside Rosalia
Everything above resolves to Rosalia as a whole — one PHZM band and one 28°F frost record, read across 402 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 Rosalia Average
Rosalia Average
- ●USDA Zones 6b, averaged across Rosalia
- ●One soil character for all of Rosalia
- ●Frost dates read at Rosalia's scale: Apr 22 to Oct 14
YOUR Parcel
- ✓Your exact zone, not Rosalia's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Rosalia
Pull a site-specific report for your exact address in Rosalia, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Rosalia averages can't show:
We read public map data around Rosalia — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rosalia average
How we know this about Rosalia
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 Rosalia’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 Rosalia
When does frost risk typically end in Rosalia?
The last hard freeze (28°F) in Rosalia typically lands around Apr 22, 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 13.
When is the first frost in Rosalia?
The first hard freeze (28°F) in Rosalia typically arrives around Oct 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 30, so the watching starts about Sep 14 — about 175 days after the spring freeze cleared.
How long is the growing season in Rosalia?
Measured between 28°F hard freezes, Rosalia sees about 175 frost-free days — roughly Apr 22 through Oct 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 13 to Sep 30, about 140 days.
Is the soil safe to grow vegetables in Rosalia?
The federal record around Rosalia shows 51 documented sites, mostly Underground Storage Tanks entries (38), the nearest Underground Storage Tanks record about 0.3 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 Rosalia?
From about Sep 14 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 14 (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 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Rosalia's scale — its 6b band and its 175-day season. Your yard writes its own version of Rosalia'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 Rosalia’s own scale
6 of the readings below were taken at Rosalia's own scale — its own ~175-day season between 28°F freezes, the 402 acres it covers and 51 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Rosalia's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Rosalia's own 28°F hard-freeze dates, about Apr 22 and Oct 14 and the ~175-day span between themNOAA 1991–2020 Climate Normals
- 51 documented contamination sites on the federal record near Rosalia, the closest Underground Storage Tanks record about 0.3 miles out from the town centreFederal environmental registers
- Rosalia's boundary and the 402 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~175-day seasonGrowable Ground crop-matching engine
- The ecoregion at Rosalia's own centroid, the Columbia PlateauUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Rosalia's 402 acres read through its county's SSURGO summaryfrom Whitman County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Whitman County
- The growing challenges every Washington grower plans around — written at state scale, so they stay on the state guidefrom Washington
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Whitman County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Rosalia's 402 acreswhy one lot differs from the next →
- Which side of Rosalia you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 402 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Rosalia-wide figureread your own land →
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