Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 21721 — Chewsville, MD

ZIP code 21721 (Chewsville, Washington County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 25 and the first fall frost October 19.

Where ZIP 21721 is

tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone7a0 to 5 °F
Coldest night−17.8 to −15 °C
Last frostApr 25
First frostOct 19
2012 zone6b

Was 6b on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Chewsville, MD…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Chewsville, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 25median — 50% chance of a later frost
Safe for tender plantsMay 11only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 6
Growing season176 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 11 and returns around October 30.

From the NOAA station Smithsburg 2nw, MD — 3 miles away, elevation 669 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 21721

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 14 – Mar 28
SpinachSow outdoors · Mar 14 – Apr 4
Broccoli, cabbageStart indoors · Feb 14 – Feb 28
Broccoli, cabbageTransplant · Apr 4 – Apr 18
Onion setsPlant outdoors · Mar 28 – Apr 11
PotatoesPlant outdoors · Apr 4 – Apr 18
LettuceSow outdoors · Mar 28 – Apr 11
Carrots, beetsSow outdoors · Apr 4 – Apr 18
TomatoesStart indoors · Feb 28 – Mar 14
TomatoesTransplant · May 2 – May 16
Peppers, eggplantStart indoors · Feb 14 – Feb 28
Peppers, eggplantTransplant · May 9 – May 23
BeansSow outdoors · May 2 – May 16
Sweet cornSow outdoors · May 2 – May 16
Cucumbers, squashSow outdoors · May 2 – May 16
Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7
GarlicPlant cloves · Oct 5 – Nov 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 25) and first fall frost (Oct 19) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 21721 came on Mar 12 — 10 days earlier than the 1991–2020 average (Mar 22).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 7a in Maryland

612 plants native to the lower 48 states, recorded in Maryland, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 82

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 126

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °F

Wildflowers & perennials 203

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °FAmerican spongeplant0.5 ft · blooms mid spring · high shade tolerance · to −24 °F

Grasses 175

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 12

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Fheartleaf peppervine2 ft · blooms late spring · low shade tolerance · to −8 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Chewsville, MD.

Soil in Chewsville, MD

The soil mapped at the center of ZIP 21721 is Lindside — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if protected from flooding or not frequently flooded during the growing seasonUSDA classification

Map unit: Lindside silt loam.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 21721; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Chewsville, MD

Summer high86 °Faverage high, July
Winter low22 °Faverage low, January
Hot days20days a year at 90 °F or more
Freezing nights122nights a year at 32 °F or less
Growing degree days3,218base 50 °F — the season’s usable heat
Longest day14 h 59 mindaylight on June 21
Shortest day9 h 22 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation43.5 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 39 °F, low 22 °F 39°22° JanFebruary: average high 42 °F, low 22 °F 42°22° FebMarch: average high 51 °F, low 29 °F 51°29° MarApril: average high 63 °F, low 39 °F 63°39° AprMay: average high 72 °F, low 49 °F 72°49° MayJune: average high 81 °F, low 59 °F 81°59° JunJuly: average high 86 °F, low 63 °F 86°63° JulAugust: average high 84 °F, low 61 °F 84°61° AugSeptember: average high 77 °F, low 54 °F 77°54° SepOctober: average high 66 °F, low 42 °F 66°42° OctNovember: average high 53 °F, low 32 °F 53°32° NovDecember: average high 43 °F, low 26 °F 43°26° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.23 in precipitation 3.2 JanFebruary: 2.66 in precipitation 2.7 FebMarch: 3.90 in precipitation 3.9 MarApril: 3.87 in precipitation 3.9 AprMay: 4.31 in precipitation 4.3 MayJune: 3.43 in precipitation 3.4 JunJuly: 3.66 in precipitation 3.7 JulAugust: 3.66 in precipitation 3.7 AugSeptember: 4.80 in precipitation 4.8 SepOctober: 3.42 in precipitation 3.4 OctNovember: 2.92 in precipitation 2.9 NovDecember: 3.69 in precipitation 3.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Smithsburg 2nw, MD (3 mi away); precipitation: Hagerstown 1 E, MD (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

217427a
Hagerstown, MD · 3 mi
217207a
Cavetown, MD · 3 mi
217347a
Funkstown, MD · 4 mi
217417a
Hagerstown, MD · 4 mi
217477b
Hagerstown, MD · 4 mi
217497b
Hagerstown, MD · 4 mi
217837a
Smithsburg, MD · 5 mi
217407a
Hagerstown, MD · 6 mi

Maryland planting zones →

Questions about 21721

What planting zone is ZIP code 21721?

ZIP code 21721 (Chewsville, MD) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Chewsville, MD?

The median last spring frost (32 °F) near 21721 is April 25; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Smithsburg 2nw station.

When is the first frost in Chewsville, MD?

The median first fall frost near 21721 is October 19, giving a median frost-free growing season of 176 days.

When should I plant tomatoes in 21721?

Start tomato seeds indoors around Feb 28 – Mar 14 and set transplants outside around May 2 – May 16, one to three weeks after the median last frost.

How much rain and snow does 21721 get?

About 43.5 inches of precipitation a year (NOAA 1991–2020 normals, Hagerstown 1 E station).

How hot do summers get in Chewsville, MD?

The average high peaks at 86 °F in July, with about 20 days a year at 90 °F or more.

What kind of soil does 21721 have?

The USDA soil survey maps Lindside at the center of ZIP 21721: silt loam, moderately well drained, pH about 7.0 (neutral).

Did spring come early in Chewsville, MD in 2026?

Spring leaf-out near 21721 came on Mar 12 in 2026, 10 days earlier than the 1991–2020 average (Mar 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Chewsville, MD?

Intermediate onions: the longest day near 21721 is 14 h 59 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 21721 change?

Yes. The 2012 USDA map put 21721 in zone 6b; the 2023 map puts it in zone 7a. The newer map uses 1991–2020 data and more weather stations.