Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Southern Md Facility, MD

Southern Md Facility, MD is in USDA zone 7b across its 2 ZIP codes. The median last spring frost is April 9 and the first fall frost October 29.

Southern Md Facility on the zone map

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

ZIP codes2

Last frostApr 9

First frostOct 29

Growing season203 days

7b 2 ZIPs

Frost forecast — next 7 nights

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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 Southern Md Facility, MD

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 9median — 50% chance of a later frost

Safe for tender plantsApril 24only 10% chance of frost after

First fall frostOctober 29median — 10% chance by Oct 14

Growing season203 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 30 and returns around November 10.

From the NOAA station Upper Marlboro 3 Nnw, MD, elevation 131 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 Southern Md Facility

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 26 – Mar 12

SpinachSow outdoors · Feb 26 – Mar 19

Broccoli, cabbageStart indoors · Jan 29 – Feb 12

Broccoli, cabbageTransplant · Mar 19 – Apr 2

Onion setsPlant outdoors · Mar 12 – Mar 26

PotatoesPlant outdoors · Mar 19 – Apr 2

LettuceSow outdoors · Mar 12 – Mar 26

Carrots, beetsSow outdoors · Mar 19 – Apr 2

TomatoesStart indoors · Feb 12 – Feb 26

TomatoesTransplant · Apr 16 – Apr 30

Peppers, eggplantStart indoors · Jan 29 – Feb 12

Peppers, eggplantTransplant · Apr 23 – May 7

BeansSow outdoors · Apr 16 – Apr 30

Sweet cornSow outdoors · Apr 16 – Apr 30

Cucumbers, squashSow outdoors · Apr 16 – Apr 30

Fall lettuce, spinachSow outdoors · Sep 3 – Sep 17

GarlicPlant cloves · Oct 15 – Nov 19

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 9) and first fall frost (Oct 29) 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 20697 came on Mar 10 — about the same time as the 1991–2020 average (Mar 12).

average
Mar 122026
Mar 10

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.

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 Southern Md Facility, MD.

Soil in Southern Md Facility, MD

The soil mapped at the center of ZIP 20697 is Sassafras — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding

pH4.9strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Sassafras-Urban land 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 20697; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Southern Md Facility, MD

Summer high88 °Faverage high, July

Winter low25 °Faverage low, January

Hot days32days a year at 90 °F or more

Freezing nights103nights a year at 32 °F or less

Growing degree days3,960base 50 °F — the season’s usable heat

Longest day14 h 53 mindaylight on June 21

Shortest day9 h 26 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation46.5 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Upper Marlboro 3 Nnw, MD (6 mi away); precipitation: Suitland 2.1 Se, MD (2 mi away). Daylight is calculated from latitude.

ZIP codes in Southern Md Facility

Maryland planting zones →

Questions about Southern Md Facility

What planting zone is Southern Md Facility, MD?

Southern Md Facility, MD is in USDA hardiness zone 7b on the 2023 map (7b: 5 to 10 °F).

When is the last frost in Southern Md Facility, MD?

The median last spring frost is April 9 and the median first fall frost is October 29 (NOAA 1991–2020 normals, Upper Marlboro 3 Nnw station).

When can I plant a garden in Southern Md Facility, MD?

Cool-season crops like peas and spinach go in around Feb 26 – Mar 19; tomatoes, peppers, beans and squash after about Apr 16, once frost risk has passed.

What kind of onions grow in Southern Md Facility, MD?

Intermediate onions: the longest day is 14 h 53 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Southern Md Facility, MD get?

About 46.5 inches of precipitation a year (NOAA 1991–2020 normals).