What Grows in Washington Grove, Maryland

USDA Zones 7b · 215 acres

Washington Grove, Maryland, sits in USDA hardiness zone 7b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.

Growers here do well with cabbage, prickly pear, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.

Score your parcel · free

Even in Washington Grove, 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 Washington Grove 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 Washington Grove — soil, climate, flood, and parcel records. How we handle your address.

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Washington Grove — the short answer

Washington Grove, Maryland: USDA zone 7b, about 227 days between hard freezes, across 215 acres of town.

USDA zone
7b
USDA PHZM 2023
Last hard freeze (28°F)
Mar 29
NOAA 1991–2020 Climate Normals, 28°F — this town
First hard freeze (28°F)
Nov 11
NOAA 1991–2020 Climate Normals, 28°F — this town
Days between freezes
~227
NOAA 1991–2020 Climate Normals, 28°F — this town
Town area
215 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

7b7b
3a (Cold)13b (Hot)

Zone 7b is Washington Grove's average, not your lot's — a low corner or a tree line moves it. Against Washington Grove's 227-day season, see what your own ground reads.

Soil varies lot by lot — soil types explained.

What this means for growing in Washington Grove

Each reading below is measured for Washington Grove itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length

Measured

Washington Grove 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

Measured

Washington Grove 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 Washington Grove is in

Washington Grove sits in the Northern Piedmont — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Washington Grove's own centroid rather than borrowed from Montgomery County.

What that means for soil

What Grows in Washington Grove

Every plant below cleared Washington Grove's own zone 7b and its 227-day season. Each card opens that plant's Maryland profile. How we score.

cabbage, photograph
Growing cabbage in MarylandZones 2–11Washington Grove's 7b — 5 zones of cold margin.
prickly pear, photograph
Maryland prickly pear guideZones 5–10Washington Grove's 7b — 2 zones of cold margin.
California poppy, photograph
California poppy in MarylandZones 6–10Washington Grove's 7b — 1 zone of cold margin.
collard greens, photograph
Collard greens: Maryland growing notesZones 2–11Washington Grove's 7b — 5 zones of cold margin.
fig, photograph
Growing fig in MarylandZones 6–10Washington Grove's 7b — 1 zone of cold margin.
lavender, photograph
Maryland lavender guideZones 5–8Washington Grove's 7b — 2 zones of cold margin.
garlic, photograph
Garlic in MarylandZones 2–10Washington Grove's 7b — 5 zones of cold margin.
grape, photograph
Grape: Maryland growing notesZones 6–9Washington Grove's 7b — 1 zone of cold margin.
Turkish rocket, photograph
Growing turkish rocket in MarylandWashington Grove's 227 days clear the ~90 it needs.
kale, photograph
Maryland kale guideZones 2–11Washington Grove's 7b — 5 zones of cold margin.
hazelnut, photograph
Hazelnut in MarylandZones 4–9Washington Grove's 7b — 3 zones of cold margin.
lentil, photograph
Lentil: Maryland growing notesZones 2–11Washington Grove's 227 days clear the ~70 it needs.
pawpaw, photograph
Growing pawpaw in MarylandZones 5–9Washington Grove's 7b — 2 zones of cold margin.
okra, photograph
Maryland okra guideZones 2–12Washington Grove's 227 days clear the ~50 it needs.
potato, photograph
Potato in MarylandZones 2–11Washington Grove's 7b — 5 zones of cold margin.
iris, photograph
Iris: Maryland growing notesZones 3–10Washington Grove's 7b — 4 zones of cold margin.
sunflower, photograph
Growing sunflower in MarylandZones 2–11Washington Grove's 227 days clear the ~70 it needs.
Apache plume, photograph
Maryland apache plume guideZones 5–11Washington Grove's 7b — 2 zones of cold margin.
hops, photograph
Hops in MarylandZones 3–8Washington Grove's 7b — 4 zones of cold margin.
hosta, photograph
Hosta: Maryland growing notesZones 3–8Washington Grove's 7b — 4 zones of cold margin.
French marigold, photograph
Growing french marigold in MarylandWashington Grove's 227 days clear the ~50 it needs.
holly, photograph
Maryland holly guideZones 5–11Washington Grove's 7b — 2 zones of cold margin.
Virginia creeper, photograph
Virginia creeper in MarylandZones 3–9Washington Grove's 7b — 4 zones of cold margin.
tulip, photograph
Tulip: Maryland growing notesZones 6–8Washington Grove's 7b — 1 zone of cold margin.
Douglas fir, photograph
Growing douglas fir in MarylandZones 4–10Washington Grove's 7b — 3 zones of cold margin.
Ethiopian mustard, photograph
Maryland ethiopian mustard guideZones 4–10Washington Grove's 7b — 3 zones of cold margin.
Kentucky bluegrass, botanical illustration
Kentucky bluegrass in MarylandZones 2–7Washington Grove's 7b — 5 zones of cold margin.
western red cedar, photograph
Western red cedar: Maryland growing notesZones 4–10Washington Grove's 7b — 3 zones of cold margin.
Japanese millet, photograph
Growing japanese millet in MarylandZones 5–10Washington Grove's 227 days clear the ~45 it needs.
ajuga, photograph
Maryland ajuga guideZones 5–11Washington Grove's 7b — 2 zones of cold margin.

Is it too late to plant in Washington Grove?

Almost never — the real question is what to plant next. 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. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.

Documented around Washington Grove

Spotted lanternfly documented 3 miles from Washington Grove, first recorded 2018. What to watch for.

What's on the federal record near Washington Grove

Closest first, within ~10 miles of Washington Grove. Listing isn't leaking, and distance isn't exposure.

  1. SPIRENT COMMUNICATIONSToxics Release Inventory · 2100 ft
  2. ROBERTS OXYGEN CO INCBrownfields · 2200 ft
  3. Cable TV MontgomeryUnderground Storage Tanks · 2200 ft
  4. Roberts Oxygen Company, Inc.Underground Storage Tanks · 2200 ft
  5. WLK, LLCUnderground Storage Tanks · 0.5 mi
  6. Old Gaithersburg Depot SiteUnderground Storage Tanks · 0.5 mi
  7. Gaithersburg Highway DepotUnderground Storage Tanks · 0.5 mi
  8. WASHINGTON GROVE ELEMENTARY SCHOOLBrownfields · 0.6 mi
  9. HAN'S AUTO CENTERBrownfields · 0.6 mi
  10. Chesapeake Petroleum & Supply CompanyUnderground Storage Tanks · 0.6 mi
  11. United Pest ControlUnderground Storage Tanks · 0.7 mi
  12. PRINTING SERVICES INTL INCBrownfields · 0.7 mi

6 more sites are on the record inside the same radius. See them on the map

Measured from Washington Grove'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 Washington Grove.

Total Sites

1,772

within ~10 miles of Washington Grove

Risk Level

Elevated

Highest-severity

8 Superfund sites (none NPL-listed)

Severity Distribution

within ~10 miles of Washington Grove

High1Moderate350Low1,421

Highest-Severity Sites

City of Rockville
PFAS Sampling · PFAS Detected
10101 Grosvenor Park Condo
Underground Storage Tanks · Open UST(S)
20036 Airpark Exxon
Underground Storage Tanks · Open UST(S)
22800 Courthouse Exxon
Underground Storage Tanks · Open UST(S)
24444 Wildwood Manor Exxon
Underground Storage Tanks · Open UST(S)

Know Before You Grow

  • Near a brownfield, raised beds of imported soil give your food clean ground.
  • Underground tanks leak petroleum as they age — near a former filling station, test the soil.
  • On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Free Report

Check your specific parcel in Washington Grove

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 Washington Grove average

Your land is one point inside Washington Grove

Everything above resolves to Washington Grove as a whole — one PHZM band and one 28°F frost record, read across 215 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 Washington Grove Average

Washington Grove Average

  • USDA Zones 7b, averaged across Washington Grove
  • One soil character for all of Washington Grove
  • Frost dates read at Washington Grove's scale: Mar 29 to Nov 11

YOUR Parcel

  • Your exact zone, not Washington Grove's 7b
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free Report

Read your specific parcel in Washington Grove

Pull a site-specific report for your exact address in Washington Grove, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your lot that Washington Grove averages can't show:

Your soil pHYour frost-free days — Washington Grove averages 227Your sun & shade

We read public map data around Washington Grove — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Washington Grove average

How we know this about Washington Grove

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 Washington Grove’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 Washington Grove

When does frost risk typically end in Washington Grove?

The last hard freeze (28°F) in Washington Grove 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.

When is the first frost in Washington Grove?

The first hard freeze (28°F) in Washington Grove typically arrives around Nov 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 28, so the watching starts about Oct 12 — about 227 days after the spring freeze cleared.

How long is the growing season in Washington Grove?

Measured between 28°F hard freezes, Washington Grove 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 Washington Grove?

The federal record around Washington Grove is a meaningful one — 1,772 documented sites, mostly Brownfields entries (836), the nearest Toxics Release Inventory record about 0.4 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 Washington Grove?

From about Oct 12 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 Nov 11 (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 Nov 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.

Everything above is measured at Washington Grove's scale — its 7b band and its 227-day season. Your yard writes its own version of Washington Grove'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 Washington Grove’s own scale

7 of the readings below were taken at Washington Grove's own scale — its own ~227-day season between 28°F freezes, the 215 acres it covers and 1,772 documented sites around it; 4 are borrowed from a wider read, named and linked below.

Measured here

  • Washington Grove's own USDA hardiness band, zones 7bUSDA PHZM 2023
  • Washington Grove's own 28°F hard-freeze dates, about Mar 29 and Nov 11 and the ~227-day span between themNOAA 1991–2020 Climate Normals
  • 1,772 documented contamination sites on the federal record near Washington Grove, the closest Toxics Release Inventory record about 0.4 miles out from the town centreFederal environmental registers
  • Washington Grove's boundary and the 215 acres inside itUS Census TIGER/Line 2025
  • Which of 1,086 plants clear zones 7b and a ~227-day seasonGrowable Ground crop-matching engine
  • The ecoregion at Washington Grove's own centroid, the Northern PiedmontUS EPA Level III Ecoregions
  • A documented spotted-lanternfly record within reach of Washington Grovelydemapr (De Bona & Helmus), 10 km survey lattice

Inherited from a wider read

  • Soil character — no town-scale survey exists, so Washington Grove's 215 acres read through its county's SSURGO summaryfrom Montgomery County
  • Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Montgomery County
  • The growing challenges every Maryland grower plans around — written at state scale, so they stay on the state guidefrom Maryland
  • Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Montgomery County

What this page can’t tell you

  • The soil pH, drainage, sun hours, and frost pockets on any one lot among Washington Grove's 215 acreswhy one lot differs from the next
  • Which side of Washington Grove you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 215 acresreading your own microclimate
  • How close that record sits to YOUR lot — the closest Toxics Release Inventory record about 0.4 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 Washington Grove-wide figureread your own land
The next step finer is your own address