Manassas city, in Virginia, sits in USDA hardiness zone 7a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, hazelnut, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Manassas city holds more than one microclimate.
Soils and elevations shift across Manassas 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 Manassas city — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Manassas city — the short answer
Manassas city, Virginia: USDA zone 7a, about 220 days between hard freezes, across 6K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 29
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~220
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 6K 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 7a is Manassas city's average, not your lot's — a low corner or a tree line moves it. Against Manassas city's 220-day season, see what your own ground reads.
Heat in Manassas city
Across a year, Manassas city accumulates about 3,697 growing degree days above 50°F, about 37 fewer than the middle Virginia county — ahead of 61 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 Manassas County
Detailed USDA soil-survey (SSURGO) mapping is limited across Manassas County, so there isn't a reliable county-wide soil summary to show here yet — a gap in the national survey, not in the ground itself.
Soil still varies lot by lot — soil types explained.
What this means for growing in Manassas city
Each reading below is measured for Manassas city itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredManassas city runs about 220 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
MeasuredManassas city 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 Manassas city is in
Manassas city sits in the Northern Piedmont — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Manassas city
We scored all 1,086 plants against Manassas city's own USDA zone 7a and its own 220-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 Manassas 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 4 — 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.
Documented around Manassas city
Spotted lanternfly documented 3 miles from Manassas city, first recorded 2020. What to watch for.
- monarch butterfly14 documented records
Sighting records, so they follow observers as much as insects.
Safe to Grow Here?
What the federal record shows across Manassas County — and how to grow with it.
We checked the federal record across Manassas County — 176 documented sites across 4 of the 9 source types we track.
The most significant on record: 6 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across Manassas County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Manassas city
Closest first, across Manassas County. Listing isn't leaking, and distance isn't exposure.
- VIRGINIA TECH OCCOQUAN ARECBrownfields · 800 ft
- GREGORY CONSTRUCTION CO INCUnderground Storage Tanks · 800 ft
- CONTINENTAL TELEPHONE COMPANY OF VIRGINIAUnderground Storage Tanks · 1400 ft
- SOUTHERN STATES COOP-MANASSASUnderground Storage Tanks · 1700 ft
- MANASSAS VOLUNTEER FIRE & RESCUE SQUADUnderground Storage Tanks · 1700 ft
- Social Security PropertyUnderground Storage Tanks · 1700 ft
- KINGS GROCERYUnderground Storage Tanks · 1700 ft
- GEORATOR CORPBrownfields · 2300 ft
- ROGERS AUTOMOTIVE CENTERUnderground Storage Tanks · 2300 ft
- GTE Manassas Central OfficeUnderground Storage Tanks · 2400 ft
- FORMER EXXON S/S #2-2962Underground Storage Tanks · 2400 ft
- Dean Drive Pump StationUnderground Storage Tanks · 2600 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Manassas 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 Manassas city.
Total Sites
176
across Manassas County
Risk Level
Moderate
Highest-severity
6 Toxics Release Inventory facilities
Sources Checked
across Manassas County
Severity Distribution
across Manassas 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 Manassas 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 Manassas city average
Your land is one point inside Manassas city
Everything above resolves to Manassas city as a whole — one PHZM band and one county frost record, read across 6K 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 Manassas city Average
Manassas city Average
- ●USDA Zones 7a, averaged across Manassas city
- ●One soil character for all of Manassas city
- ●Frost dates read at Manassas city's scale: Mar 29 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Manassas city's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Manassas city
Pull a site-specific report for your exact address in Manassas city, Virginia — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Manassas city averages can't show:
We read public map data around Manassas city — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Manassas city average
How we know this about Manassas 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 Manassas city carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Manassas city
When does frost risk typically end in Manassas city?
The last hard freeze (28°F) in Manassas 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 Manassas city?
Measured between 28°F hard freezes, Manassas city sees about 220 frost-free days — roughly Mar 29 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Oct 21, about 185 days.
Is the soil safe to grow vegetables in Manassas city?
The federal record around Manassas city shows 176 documented sites, mostly Underground Storage Tanks entries (89), the nearest Brownfields record about 0.1 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.
Everything above is measured at Manassas city's scale — its 7a band and its 220-day season. Your yard writes its own version of Manassas 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 Manassas city’s own scale
7 of the readings below were taken at Manassas city's own scale — its own ~220-day span between 28°F freezes and 176 documented sites inside its boundary; 2 are borrowed from a wider read, named and linked below.
Measured here
- Manassas city's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Manassas city's own 28°F hard-freeze dates and its ~220-day span between themNOAA 1991–2020 Climate Normals
- 176 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 0.1 miles outFederal environmental registers
- Manassas city's boundary and the 6,300 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~220-day seasonGrowable Ground crop-matching engine
- Manassas city sitting wholly inside the Northern PiedmontUS EPA Level III Ecoregions
- Open occurrence records documented in Manassas city for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
Inherited from a wider read
What this page can’t tell you
- How the season shifts across Manassas city — the ~220 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 Manassas city's 6,300 acreswhy one lot differs from the next →
- Which of those 176 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 Manassas cityread your own land →