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

Planting zone for 21163 — Woodstock, MD

ZIP code 21163 (Woodstock, Baltimore 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 7.

Where ZIP 21163 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 7

2012 zone6b

Was 6b on the 2012 map — a full zone warmer now. 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 Woodstock, 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 Woodstock, 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 13only 10% chance of frost after

First fall frostNovember 7median — 10% chance by Oct 27

Growing season220 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 22 and returns around November 20.

From the NOAA station Cylburn, MD — 11 miles away, elevation 236 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 21163

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 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 2) 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 21163 came on Mar 15 — about the same time as the 1991–2020 average (Mar 17).

average
Mar 172026
Mar 15

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 Woodstock, MD.

Soil in Woodstock, MD

The soil mapped at the center of ZIP 21163 is Manor — loam, well drained.

TextureLoama good balance for most vegetables

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupBwater soaks in moderately

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Manor loam, 8 to 15 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 21163; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Woodstock, MD

Summer high87 °Faverage high, July

Winter low27 °Faverage low, January

Hot days18days a year at 90 °F or more

Freezing nights92nights a year at 32 °F or less

Growing degree days3,925base 50 °F — the season’s usable heat

Longest day14 h 57 mindaylight on June 21

Shortest day9 h 23 mindaylight on December 21

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

Precipitation47.6 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: Cylburn, MD (11 mi away); precipitation: Marriottsville 0.6 Se, MD (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

211337a

Randallstown, MD · 3 mi

211047b

Marriottsville, MD · 4 mi

212447b

Windsor Mill, MD · 4 mi

210427b

Ellicott City, MD · 5 mi

210437b

Ellicott City, MD · 6 mi

217947b

West Friendship, MD · 7 mi

212077b

Gwynn Oak, MD · 7 mi

212287b

Catonsville, MD · 7 mi

Maryland planting zones →

Questions about 21163

What planting zone is ZIP code 21163?

ZIP code 21163 (Woodstock, 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 Woodstock, MD?

The median last spring frost (32 °F) near 21163 is April 2; after April 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cylburn station.

When is the first frost in Woodstock, MD?

The median first fall frost near 21163 is November 7, giving a median frost-free growing season of 220 days.

When should I plant tomatoes in 21163?

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 21163 get?

About 47.6 inches of precipitation a year (NOAA 1991–2020 normals, Marriottsville 0.6 Se station).

How hot do summers get in Woodstock, MD?

The average high peaks at 87 °F in July, with about 18 days a year at 90 °F or more.

What kind of soil does 21163 have?

The USDA soil survey maps Manor at the center of ZIP 21163: loam, well drained, pH about 5.3 (strongly acidic).

Did spring come early in Woodstock, MD in 2026?

Spring leaf-out near 21163 came on Mar 15 in 2026, about the same as the 1991–2020 average (Mar 17), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Woodstock, MD?

Intermediate onions: the longest day near 21163 is 14 h 57 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 21163 change?

Yes. The 2012 USDA map put 21163 in zone 6b; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.