Kitsap County, in Washington, sits in USDA hardiness zone 8b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Well-matched crops include cabbage, fig, 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.
Kitsap County lies within the Puget Sound Lowlands and the Pacific Northwest — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Kitsap County holds more than one microclimate.
Soils and elevations shift across Kitsap County, so your frost dates and drainage aren't the county average. 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 Kitsap County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Kitsap County — the short answer
Kitsap County, Washington: USDA zone 8b, about 285 days between hard freezes, across 253K acres.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 15
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 27
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~285
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 253K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 8b is Kitsap County's average, not your lot's — a low corner or a tree line moves it. Against Kitsap County's 285-day season, see what your own ground reads.
Heat and winter chill in Kitsap County
Across a year, Kitsap County accumulates about 1,891 growing degree days above 50°F, about 178 more than the middle Washington county — ahead of 27 of Washington’s 39 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Winter banks about 2,443 hours below 45°F. Chill is what tells a fruit tree its dormancy is over, and it is set by climate rather than by anything you can build.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Kitsap County
Across Kitsap County, the ground is predominantly Inceptisols, where Alderwood, Harstine, and Shelton are the most extensive named soil series. The soil is generally moderately well drained with a gravelly ashy sandy loam surface. Topsoil pH runs about 5.3–5.8, strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Inceptisols
Drainage
Moderately well drained
Prime farmland
10%
Hydric soils
7%
Soil still varies lot by lot — soil types explained.
How the ground varies across Kitsap County
The USDA soil survey maps 69% of Kitsap County as moderately well drained — but another 29% drains differently: 11% well drained, 8% somewhat excessively drained.
Alderwood is the most extensive named soil at 18% of mapped acres, then Harstine (14%) and Shelton (11%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Kitsap County
Each reading below is measured for Kitsap County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Kitsap County are moderately well drained, in hydrologic group B — roughly the middle of the drainage range.
This is close to the middle most vegetables prefer: it holds enough water to carry a crop between rains without staying waterlogged. The catch is that a wet spring or a low corner can still tip it soggy.
Plant on the site as-is for most crops, but keep the lowest, slowest-draining beds for moisture-tolerant plantings.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Kitsap County runs about pH 5.3–5.8, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredKitsap County runs about 285 days between hard freezes — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredKitsap County sits in USDA hardiness zone 8b.
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 Kitsap County is in
Kitsap County sits in the Puget Lowland — EPA Level III, inside the wider Marine West Coast Forest. One consistent ecological setting across the whole county.
What Grows in Kitsap County
We scored all 1,086 plants against Kitsap County's own USDA zone 8b and its own 285-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Washington profile.
Is it too late to plant in Kitsap County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 27 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
Documented around Kitsap County
- monarch butterfly3 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Kitsap County
USGS estimates 654 lb of Glyphosate on Kitsap County farmland in 2019, its largest by weight, ahead of Chlorpyrifos (458 lb) and 2,4-d (324 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Kitsap County — and how to grow with it.
We checked the federal record across Kitsap County — 1,100 documented sites across 7 of the 9 source types we track.
The most significant on record: 18 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Kitsap County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Kitsap County
Closest first, across Kitsap County. Listing isn't leaking, and distance isn't exposure.
- HANDY ANDY'SUnderground Storage Tanks · 1700 ft
- PUMP STATION 20Underground Storage Tanks · 0.6 mi
- PUMP STATION 6Underground Storage Tanks · 0.6 mi
- 25N/01E-23D01Nitrate · 0.7 mi
- CENTRAL KITSAP FIRE AND RESCUEUnderground Storage Tanks · 0.8 mi
- 25N/01E-23K01Nitrate · 0.8 mi
- KITSAP CNTY FAIR PAVILLIONBrownfields · 0.8 mi
- PUMP STATION 7Underground Storage Tanks · 0.9 mi
- PUMP STATION 19Underground Storage Tanks · 0.9 mi
- CENTRAL KITSAP OLYMPIC HS CKSD 401Brownfields · 1.0 mi
- CENTRAL KITSAP SCHOOL DISTRICTUnderground Storage Tanks · 1.0 mi
- FAIRGROUND'S MARKETUnderground Storage Tanks · 1.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Kitsap County'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 Kitsap County.
Sources Checked
across Kitsap County
Severity Distribution
across Kitsap County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Kitsap County, two things run higher than the national average across Kitsap County — Nitrate (486 sites) and PFAS (15 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Kitsap County
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 Kitsap County average
Your land is one point inside Kitsap County
Everything above resolves to Kitsap County as a whole — one PHZM band and one county frost record, read across 253K 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 county 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 county average.
Your Lot vs the Kitsap County Average
Kitsap County Average
- ●USDA Zones 8b, averaged across Kitsap County
- ●One soil character for all of Kitsap County
- ●Frost dates read at Kitsap County's scale: Feb 15 to Nov 27
YOUR Parcel
- ✓Your exact zone, not Kitsap County's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Kitsap County
Pull a site-specific report for your exact address in Kitsap County, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Kitsap County averages can't show:
We read public map data around Kitsap County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Kitsap County average
How we know this about Kitsap County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Kitsap County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Kitsap County
When does frost risk typically end in Kitsap County?
The last hard freeze (28°F) in Kitsap County typically lands around Feb 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 Mar 8.
How long is the growing season in Kitsap County?
Measured between 28°F hard freezes, Kitsap County sees about 285 frost-free days — roughly Feb 15 through Nov 27, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 8 to Nov 13, about 250 days.
Is the soil safe to grow vegetables in Kitsap County?
The federal record around Kitsap County runs heavier than most — 1,100 documented sites, mostly Nitrate entries (486), the nearest Underground Storage Tanks record about 0.3 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Everything above is measured at Kitsap County's scale — its 8b band and its 285-day season. Your yard writes its own version of Kitsap County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Washington's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Kitsap County’s own scale
9 of the readings below were taken at Kitsap County's own scale — its own ~285-day span between 28°F freezes, the 3 most extensive soil series mapped here and 1,100 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Kitsap County's own USDA hardiness band, zones 8bUSDA PHZM 2023
- Kitsap County's own 28°F hard-freeze dates and its ~285-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Kitsap CountyUSDA NRCS SSURGO
- 1,100 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.3 miles outFederal environmental registers
- Kitsap County's boundary and the 252,856 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~285-day seasonGrowable Ground crop-matching engine
- Kitsap County sitting wholly inside the Puget LowlandUS EPA Level III Ecoregions
- Open occurrence records documented in Kitsap County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Kitsap County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Washington grower plans around — written at state scale, so they stay on the state guidefrom Washington
What this page can’t tell you
- How the season shifts across Kitsap County — the ~285 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Kitsap County's 252,856 acreswhy one lot differs from the next →
- Which of those 1,100 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Kitsap Countyread your own land →