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

Planting zone for 21875 — Delmar, MD

ZIP code 21875 (Delmar, Wicomico County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 2 and the first fall frost November 10.

Where ZIP 21875 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 2
First frostNov 10
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 Delmar, 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 Delmar, MD

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 2median — 50% chance of a later frost
Safe for tender plantsApril 16only 10% chance of frost after
First fall frostNovember 10median — 10% chance by Oct 29
Growing season222 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 20 and returns around November 24.

From the NOAA station Salisbury 2n, MD — 3 miles away, elevation 20 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 21875

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 19 – Mar 5
SpinachSow outdoors · Feb 19 – Mar 12
Broccoli, cabbageStart indoors · Jan 22 – Feb 5
Broccoli, cabbageTransplant · Mar 12 – Mar 26
Onion setsPlant outdoors · Mar 5 – Mar 19
PotatoesPlant outdoors · Mar 12 – Mar 26
LettuceSow outdoors · Mar 5 – Mar 19
Carrots, beetsSow outdoors · Mar 12 – Mar 26
TomatoesStart indoors · Feb 5 – Feb 19
TomatoesTransplant · Apr 9 – Apr 23
Peppers, eggplantStart indoors · Jan 22 – Feb 5
Peppers, eggplantTransplant · Apr 16 – Apr 30
BeansSow outdoors · Apr 9 – Apr 23
Sweet cornSow outdoors · Apr 9 – Apr 23
Cucumbers, squashSow outdoors · Apr 9 – Apr 23
Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29
GarlicPlant cloves · Oct 27 – Dec 1
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 2) and first fall frost (Nov 10) 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 21875 came on Mar 10 — about the same time as the 1991–2020 average (Mar 8).

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 Delmar, MD.

Soil in Delmar, MD

The soil mapped at the center of ZIP 21875 is Lenni — moderately decomposed plant material, poorly drained.

TextureModerately decomposed plant materialtop layer
pH4.5strongly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter94%high
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Lenni sandy loam, 0 to 2 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 21875; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Delmar, MD

Summer high88 °Faverage high, July
Winter low29 °Faverage low, January
Hot days31days a year at 90 °F or more
Freezing nights72nights a year at 32 °F or less
Growing degree days4,352base 50 °F — the season’s usable heat
Longest day14 h 51 mindaylight on June 21
Shortest day9 h 29 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation47.7 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 51 °F, low 31 °F 51°31° FebMarch: average high 57 °F, low 37 °F 57°37° MarApril: average high 69 °F, low 45 °F 69°45° AprMay: average high 77 °F, low 55 °F 77°55° MayJune: average high 84 °F, low 64 °F 84°64° JunJuly: average high 88 °F, low 69 °F 88°69° JulAugust: average high 86 °F, low 67 °F 86°67° AugSeptember: average high 80 °F, low 61 °F 80°61° SepOctober: average high 70 °F, low 50 °F 70°50° OctNovember: average high 60 °F, low 40 °F 60°40° NovDecember: average high 51 °F, low 33 °F 51°33° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 3.44 in precipitation 3.4 JanFebruary: 3.00 in precipitation 3.0 FebMarch: 4.24 in precipitation 4.2 MarApril: 3.49 in precipitation 3.5 AprMay: 3.96 in precipitation 4.0 MayJune: 4.29 in precipitation 4.3 JunJuly: 4.66 in precipitation 4.7 JulAugust: 4.86 in precipitation 4.9 AugSeptember: 4.56 in precipitation 4.6 SepOctober: 4.11 in precipitation 4.1 OctNovember: 3.27 in precipitation 3.3 NovDecember: 3.84 in precipitation 3.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Salisbury 2n, MD (3 mi away); precipitation: Delmar 0.2 Ne, MD (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

199407b
Delmar, DE · 3 mi
218027b
Salisbury, MD · 6 mi
218037b
Salisbury, MD · 6 mi
218497b
Parsonsburg, MD · 7 mi
199567b
Laurel, DE · 7 mi
218047b
Salisbury, MD · 9 mi
218267b
Fruitland, MD · 9 mi
218017b
Salisbury, MD · 10 mi

Maryland planting zones →

Questions about 21875

What planting zone is ZIP code 21875?

ZIP code 21875 (Delmar, 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 Delmar, MD?

The median last spring frost (32 °F) near 21875 is April 2; after April 16 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Salisbury 2n station.

When is the first frost in Delmar, MD?

The median first fall frost near 21875 is November 10, giving a median frost-free growing season of 222 days.

When should I plant tomatoes in 21875?

Start tomato seeds indoors around Feb 5 – Feb 19 and set transplants outside around Apr 9 – Apr 23, one to three weeks after the median last frost.

How much rain and snow does 21875 get?

About 47.7 inches of precipitation a year (NOAA 1991–2020 normals, Delmar 0.2 Ne station).

How hot do summers get in Delmar, MD?

The average high peaks at 88 °F in July, with about 31 days a year at 90 °F or more.

What kind of soil does 21875 have?

The USDA soil survey maps Lenni at the center of ZIP 21875: moderately decomposed plant material, poorly drained, pH about 4.5 (strongly acidic).

Did spring come early in Delmar, MD in 2026?

Spring leaf-out near 21875 came on Mar 10 in 2026, about the same as the 1991–2020 average (Mar 8), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Delmar, MD?

Intermediate onions: the longest day near 21875 is 14 h 51 min, so day-neutral types bulb best; long-day varieties may not bulb fully.