Fairfax city, in Virginia, sits in USDA hardiness zone 7b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include cabbage, prickly pear, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Fairfax city lies within the Northern Virginia (DC Metro) and the Piedmont — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Fairfax city holds more than one microclimate.
Soils and elevations shift across Fairfax city, 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 Fairfax city — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Fairfax city — the short answer
Fairfax city, Virginia: USDA zone 7b, about 227 days between hard freezes, across 4K acres.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 29
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 11
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~227
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 4K 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 7b is Fairfax city's average, not your lot's — a low corner or a tree line moves it. Against Fairfax city's 227-day season, see what your own ground reads.
Heat in Fairfax city
Across a year, Fairfax city accumulates about 3,659 growing degree days above 50°F, about 75 fewer than the middle Virginia county — ahead of 53 of Virginia’s 133 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.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Fairfax County
Across Fairfax County, the ground is predominantly Entisols, where Wheaton, Glenelg, and Codorus are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 5.0–7.5, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Entisols
Drainage
Well drained
Prime farmland
2%
Hydric soils
1%
Soil still varies lot by lot — soil types explained.
How the ground varies across Fairfax city
The USDA soil survey maps 59% of Fairfax city as well drained — but another 6% drains differently: 5% somewhat poorly drained, 1% moderately well drained.
Wheaton is the most extensive named soil at 47% of mapped acres, then Glenelg (33%) and Codorus (7%).
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 Fairfax city
Each reading below is measured for Fairfax city itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Fairfax city are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Fairfax city runs about pH 5.0–7.5, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredFairfax city runs about 227 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
MeasuredFairfax city sits in USDA hardiness zone 7b.
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 Fairfax city is in
Fairfax city sits in the Piedmont — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Fairfax city
We scored all 1,086 plants against Fairfax city's own USDA zone 7b and its own 227-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 Virginia profile.
Is it too late to plant in Fairfax city?
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 Mar 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 11 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Fairfax city
Spotted lanternfly documented 2 miles from Fairfax city, first recorded 2022. What to watch for.
- Japanese beetle1 documented records
- monarch butterfly87 documented records
Sighting records, so they follow observers as much as insects.
Safe to Grow Here?
What the federal record shows across Fairfax County — and how to grow with it.
We checked the federal record across Fairfax County — 213 documented sites across 3 of the 9 source types we track.
The most significant on record: 7 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Fairfax County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Fairfax city
Closest first, across Fairfax County. Listing isn't leaking, and distance isn't exposure.
- ANTHONY CARUSOUnderground Storage Tanks · 600 ft
- LAYTON HALL ELEMENTARY SCHOOLUnderground Storage Tanks · 800 ft
- SAFEWAY STORE #4001Brownfields · 2000 ft
- JIM MCKAY CHEVROLET INCUnderground Storage Tanks · 2300 ft
- MCKAY CHEVROLET INCBrownfields · 2600 ft
- GENL MOTORS TRAINING CENTERBrownfields · 2600 ft
- G M TRAINING CENTERUnderground Storage Tanks · 0.5 mi
- SUNOCO #0004-4636Underground Storage Tanks · 0.5 mi
- FX CO PUB LIB FAIRFAX CITY BRBrownfields · 0.5 mi
- FAIR OAKS DODGEUnderground Storage Tanks · 0.5 mi
- AMAZON FRESH - MAB3Brownfields · 0.5 mi
- BELL ATLANTICUnderground Storage Tanks · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Fairfax city'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 Fairfax city.
Total Sites
213
across Fairfax County
Risk Level
Elevated
Highest-severity
7 Toxics Release Inventory facilities
Sources Checked
across Fairfax County
Severity Distribution
across Fairfax County
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •TRI facilities report what they release. Check the wind — downwind beds catch more of it.
Check your specific parcel in Fairfax city
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 Fairfax city average
Your land is one point inside Fairfax city
Everything above resolves to Fairfax city as a whole — one PHZM band and one county frost record, read across 4K 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 Fairfax city Average
Fairfax city Average
- ●USDA Zones 7b, averaged across Fairfax city
- ●One soil character for all of Fairfax city
- ●Frost dates read at Fairfax city's scale: Mar 29 to Nov 11
YOUR Parcel
- ✓Your exact zone, not Fairfax city's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Fairfax city
Pull a site-specific report for your exact address in Fairfax city, Virginia — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Fairfax city averages can't show:
We read public map data around Fairfax city — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Fairfax city average
How we know this about Fairfax city
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 Fairfax city carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Fairfax city
When does frost risk typically end in Fairfax city?
The last hard freeze (28°F) in Fairfax city typically lands around Mar 29, 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 19.
How long is the growing season in Fairfax city?
Measured between 28°F hard freezes, Fairfax city sees about 227 frost-free days — roughly Mar 29 through Nov 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Oct 28, about 192 days.
Is the soil safe to grow vegetables in Fairfax city?
The federal record around Fairfax city is a meaningful one — 213 documented sites, mostly Underground Storage Tanks entries (119), 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.
Everything above is measured at Fairfax city's scale — its 7b band and its 227-day season. Your yard writes its own version of Fairfax city'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 Virginia's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Fairfax city’s own scale
8 of the readings below were taken at Fairfax city's own scale — its own ~227-day span between 28°F freezes, the 3 most extensive soil series mapped here and 213 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Fairfax city's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Fairfax city's own 28°F hard-freeze dates and its ~227-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Fairfax cityUSDA NRCS SSURGO
- 213 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.1 miles outFederal environmental registers
- Fairfax city's boundary and the 3,994 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~227-day seasonGrowable Ground crop-matching engine
- Fairfax city sitting wholly inside the PiedmontUS EPA Level III Ecoregions
- Open occurrence records documented in Fairfax city for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
Inherited from a wider read
- The growing challenges every Virginia grower plans around — written at state scale, so they stay on the state guidefrom Virginia
What this page can’t tell you
- How the season shifts across Fairfax city — the ~227 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 Fairfax city's 3,994 acreswhy one lot differs from the next →
- Which of those 213 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 Fairfax cityread your own land →