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

Planting zone for 21890 — Westover, MD

ZIP code 21890 (Westover, Somerset County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 3 and the first fall frost November 7.

Where ZIP 21890 is

Outlined: the ZIP code area · 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.

Zone7b5 to 10 °F
Coldest night−15 to −12.2 °C
Last frostApr 3
First frostNov 7
2012 zone7b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Westover, 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 Westover, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 3median — 50% chance of a later frost
Safe for tender plantsApril 25only 10% chance of frost after
First fall frostNovember 7median — 10% chance by Oct 27
Growing season217 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 21 and returns around November 21.

From the NOAA station Salisbury, MD — 16 miles away, elevation 10 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 21890

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 20 – Mar 6
SpinachSow outdoors · Feb 20 – Mar 13
Broccoli, cabbageStart indoors · Jan 23 – Feb 6
Broccoli, cabbageTransplant · Mar 13 – Mar 27
Onion setsPlant outdoors · Mar 6 – Mar 20
PotatoesPlant outdoors · Mar 13 – Mar 27
LettuceSow outdoors · Mar 6 – Mar 20
Carrots, beetsSow outdoors · Mar 13 – Mar 27
TomatoesStart indoors · Feb 6 – Feb 20
TomatoesTransplant · Apr 10 – Apr 24
Peppers, eggplantStart indoors · Jan 23 – Feb 6
Peppers, eggplantTransplant · Apr 17 – May 1
BeansSow outdoors · Apr 10 – Apr 24
Sweet cornSow outdoors · Apr 10 – Apr 24
Cucumbers, squashSow outdoors · Apr 10 – Apr 24
Fall lettuce, spinachSow outdoors · Sep 12 – Sep 26
GarlicPlant cloves · Oct 24 – Nov 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 3) and first fall frost (Nov 7) 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 21890 came on Mar 10 — 5 days later than the 1991–2020 average (Mar 5).

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 7b in Maryland

618 plants native to the lower 48 states, recorded in Maryland, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. Each links to its USDA PLANTS profile.

Trees 83

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 127

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 206

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 176

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 Westover, MD.

Soil in Westover, MD

The soil mapped at the center of ZIP 21890 is Udorthents — sandy loam, well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH5.5moderately acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Udorthents complex, 0 to 5 percent slopes.

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 21890; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Westover, MD

Summer high89 °Faverage high, July
Winter low29 °Faverage low, January
Hot days31days a year at 90 °F or more
Freezing nights71nights a year at 32 °F or less
Growing degree days4,456base 50 °F — the season’s usable heat
Longest day14 h 49 mindaylight on June 21
Shortest day9 h 30 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation47.3 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 47 °F, low 29 °F 47°29° JanFebruary: average high 50 °F, low 30 °F 50°30° FebMarch: average high 58 °F, low 37 °F 58°37° MarApril: average high 69 °F, low 46 °F 69°46° AprMay: average high 77 °F, low 55 °F 77°55° MayJune: average high 85 °F, low 65 °F 85°65° JunJuly: average high 89 °F, low 70 °F 89°70° JulAugust: average high 86 °F, low 68 °F 86°68° AugSeptember: average high 81 °F, low 62 °F 81°62° SepOctober: average high 71 °F, low 50 °F 71°50° OctNovember: average high 60 °F, low 40 °F 60°40° NovDecember: average high 52 °F, low 33 °F 52°33° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 3.47 in precipitation 3.5 JanFebruary: 2.93 in precipitation 2.9 FebMarch: 4.17 in precipitation 4.2 MarApril: 3.45 in precipitation 3.5 AprMay: 3.77 in precipitation 3.8 MayJune: 4.04 in precipitation 4.0 JunJuly: 4.36 in precipitation 4.4 JulAugust: 5.30 in precipitation 5.3 AugSeptember: 4.46 in precipitation 4.5 SepOctober: 4.43 in precipitation 4.4 OctNovember: 3.21 in precipitation 3.2 NovDecember: 3.66 in precipitation 3.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Salisbury, MD (16 mi away); precipitation: Princess Anne 2.1 Ssw, MD (within 1 mile). 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.

218537b
Princess Anne, MD · 3 mi
218717b
Westover, MD · 4 mi
218367b
Manokin, MD · 4 mi
218678a
Upper Fairmount, MD · 6 mi
218577b
Rehobeth, MD · 8 mi
218107b
Allen, MD · 9 mi
218227b
Eden, MD · 9 mi
218388a
Marion Station, MD · 10 mi

All 2 ZIP codes in Westover → · Maryland planting zones →

Questions about 21890

What planting zone is ZIP code 21890?

ZIP code 21890 (Westover, MD) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Westover, MD?

The median last spring frost (32 °F) near 21890 is April 3; after April 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Salisbury station.

When is the first frost in Westover, MD?

The median first fall frost near 21890 is November 7, giving a median frost-free growing season of 217 days.

When should I plant tomatoes in 21890?

Start tomato seeds indoors around Feb 6 – Feb 20 and set transplants outside around Apr 10 – Apr 24, one to three weeks after the median last frost.

How much rain and snow does 21890 get?

About 47.3 inches of precipitation a year (NOAA 1991–2020 normals, Princess Anne 2.1 Ssw station).

How hot do summers get in Westover, MD?

The average high peaks at 89 °F in July, with about 31 days a year at 90 °F or more.

What kind of soil does 21890 have?

The USDA soil survey maps Udorthents at the center of ZIP 21890: sandy loam, well drained, pH about 5.5 (moderately acidic).

Did spring come early in Westover, MD in 2026?

Spring leaf-out near 21890 came on Mar 10 in 2026, 5 days later than the 1991–2020 average (Mar 5), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Westover, MD?

Intermediate onions: the longest day near 21890 is 14 h 49 min, so day-neutral types bulb best; long-day varieties may not bulb fully.