Zillah, Washington, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
A short list that earns its place here — cabbage, hazelnut, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Zillah, 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 Zillah 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 Zillah — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Zillah — the short answer
Zillah, Washington: USDA zone 7a, about 228 days between hard freezes, across 1K acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~228
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 1K 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 7a is Zillah's average, not your lot's — a low corner or a tree line moves it. Against Zillah's 228-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Zillah
Each reading below is measured for Zillah itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredZillah runs about 228 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredZillah sits in USDA hardiness zone 7a.
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 Zillah is in
Zillah sits in the Columbia Plateau — EPA Level III, inside the wider North American Deserts. That is read at Zillah's own centroid rather than borrowed from Yakima County.
What Grows in Zillah
Every plant below cleared Zillah's own zone 7a and its 228-day season. Each card opens that plant's Washington profile. How we score.
Is it too late to plant in Zillah?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
What's on the federal record near Zillah
Closest first, within ~10 miles of Zillah. Listing isn't leaking, and distance isn't exposure.
- Cherry Patch Mini MartUnderground Storage Tanks · 950 ft
- WESTERN IDAHO POTATO ZILLAH PLANTUnderground Storage Tanks · 1100 ft
- ZILLAH SCHOOL DISTRICT 205Underground Storage Tanks · 1700 ft
- CHEVRON WESTUnderground Storage Tanks · 1800 ft
- DEVIN SHELLUnderground Storage Tanks · 1800 ft
- ZILLAH SCHOOL DIST 205 110 2ND STBrownfields · 2300 ft
- 11N/20E-25L01Nitrate · 2600 ft
- DELP AND SONSUnderground Storage Tanks · 0.7 mi
- MT ARBOR NURSERIESUnderground Storage Tanks · 0.7 mi
- 11N/20E-36B01Nitrate · 0.7 mi
- 11N/20E-24N01Nitrate · 0.8 mi
- 11N/20E-23Q02Nitrate · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Zillah'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 Zillah.
Total Sites
444
within ~10 miles of Zillah
Risk Level
Elevated
Highest-severity
7 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Zillah
Severity Distribution
within ~10 miles of Zillah
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Zillah, two things run higher than the national average within ~10 miles of Zillah — Nitrate (362 sites) and CAFO (11 sites). That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Zillah
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 Zillah average
Your land is one point inside Zillah
Everything above resolves to Zillah as a whole — one PHZM band and one 28°F frost record, read across 1K 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 city 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 Zillah Average
Zillah Average
- ●USDA Zones 7a, averaged across Zillah
- ●One soil character for all of Zillah
- ●Frost dates read at Zillah's scale: Mar 16 to Oct 30
YOUR Parcel
- ✓Your exact zone, not Zillah's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Zillah
Pull a site-specific report for your exact address in Zillah, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Zillah averages can't show:
We read public map data around Zillah — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Zillah average
How we know this about Zillah
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Zillah’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 city grain anywhere on this page — there is no city-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 Zillah
When does frost risk typically end in Zillah?
The last hard freeze (28°F) in Zillah typically lands around Mar 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 Apr 6.
When is the first frost in Zillah?
The first hard freeze (28°F) in Zillah typically arrives around Oct 30, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 16, so the watching starts about Sep 30 — about 228 days after the spring freeze cleared.
How long is the growing season in Zillah?
Measured between 28°F hard freezes, Zillah sees about 228 frost-free days — roughly Mar 16 through Oct 30, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 6 to Oct 16, about 193 days.
Is the soil safe to grow vegetables in Zillah?
The federal record around Zillah is a meaningful one — 444 documented sites, mostly Nitrate entries (362), the nearest Underground Storage Tanks record about 0.2 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 I protect my plants from frost in Zillah?
From about Sep 30 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 30 (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 30. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Zillah's scale — its 7a band and its 228-day season. Your yard writes its own version of Zillah'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 Zillah’s own scale
6 of the readings below were taken at Zillah's own scale — its own ~228-day season between 28°F freezes, the 1,165 acres it covers and 444 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Zillah's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Zillah's own 28°F hard-freeze dates, about Mar 16 and Oct 30 and the ~228-day span between themNOAA 1991–2020 Climate Normals
- 444 documented contamination sites on the federal record near Zillah, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Zillah's boundary and the 1,165 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~228-day seasonGrowable Ground crop-matching engine
- The ecoregion at Zillah's own centroid, the Columbia PlateauUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Zillah's 1,165 acres read through its county's SSURGO summaryfrom Yakima County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Yakima 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 Yakima County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Zillah's 1,165 acreswhy one lot differs from the next →
- Which side of Zillah you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,165 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Zillah-wide figureread your own land →