What Grows in Cobb Island, Maryland

USDA Zones 6a-7b · 401 acres

Cobb Island, Maryland, sits in USDA hardiness zones 6a-7b — a zone band wide enough that plant choice, not possibility, is the interesting question.

Growers here do well with tomato, black-eyed susan, peach, and sweet corn — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.

Score your parcel · free

Even in Cobb Island, no two yards are alike.

A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Cobb Island lot. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your full report in seconds

Quick Facts

USDA Zones

6a-7b

Last Hard Freeze (28°F)

Mar 3

Town normal — light frosts run a few weeks later

First Hard Freeze (28°F)

Dec 15

Town normal — light frosts arrive a few weeks earlier

Town Area

401 acres

Hardiness Zone Range

6a
7b
3a (Cold)13b (Hot)

Zone maps are averages across Cobb Island. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.

Soil varies lot by lot — soil types explained.

Is it too late to plant in Cobb Island?

For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 15 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.

Growing Challenges in Maryland

What an experienced grower plans around here — each one has a move.

Heavy Piedmont clay drains poorly

A raised bed today, compost every fall — Piedmont clay becomes an asset once the drainage is yours.

Humidity and heat in summer promote disease

Morning watering at the base, room to breathe between plants, resistant varieties — the humid-summer basics, per your extension.

Deer pressure in suburban areas is extreme

A tall fence is the answer that holds; for everything outside it, lean toward the plants deer reliably skip.

For cultivar selection, pest pressure, and planting-time guidance specific to Maryland, the University of Maryland Extension is the authoritative local source.

Environmental Intelligence

Understanding what's nearby helps you make informed decisions about where and how to grow.

Total Sites

206

within ~10 miles of Cobb Island

Risk Level

Elevated

Highest-severity

2 Toxics Release Inventory facilities

Severity Distribution

within ~10 miles of Cobb Island

High0Moderate78Low128

Highest-Severity Sites

Bma Services LLC / Morgantown Plant
Toxics Release Inventory · 20664bmsrv12620
Capt. John'S Crabhouse
Underground Storage Tanks · Open UST(S)
Ch Ee 16
Nitrate Monitoring · Well
Ch Ee 16
Nitrate Monitoring · Well
Ch Ee 43
Nitrate Monitoring · Well

A note from Gnorman

What an experienced grower watches for around here

In and around Cobb Island, two things run higher than the national average — Nitrate (61 sites) and Underground Storage Tanks (128 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.

Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.

Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.

Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).

Use raised beds with imported soil — this eliminates the primary soil-contact pathway.

Free Report

Check your specific parcel in Cobb Island

Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Your Specific Parcel Matters

Cobb Island Average

  • USDA Zones 6a-7b
  • Generic soil type for the area
  • State-average frost dates

YOUR Parcel

  • Your exact hardiness zone
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free Report

Read your specific parcel in Cobb Island

Pull a site-specific report for your exact address in Cobb Island, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Key Growing Facts for Cobb Island, Maryland

  • USDA Hardiness Zones: 6a-7b (USDA PHZM 2023)
  • Last Hard Freeze (28°F): Mar 3 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
  • First Hard Freeze (28°F): Dec 15 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
  • Days Between Hard Freezes: ~287 (town normal, NOAA 1991–2020 Climate Normals)
  • Land Area: 401 acres (US Census TIGER 2025)

Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.

Frequently Asked Questions

What hardiness zone is Cobb Island, Maryland?

Cobb Island sits in USDA hardiness zones 6a-7b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.

Is it too late to plant in Cobb Island?

For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 15 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.

When does frost risk typically end in Cobb Island?

The last hard freeze (28°F) in Cobb Island typically lands around Mar 3, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.

When is the first frost in Cobb Island?

The first hard freeze (28°F) in Cobb Island typically arrives around Dec 15, per NOAA 1991–2020 climate normals — the point most tender summer crops finish. Lighter frosts usually reach a couple of weeks earlier, so watch the forecast from late summer on and harvest or cover tender plants before the first cold night.

What vegetables grow in Cobb Island?

Cobb Island's zones 6a-7b support a wide range — strong performers include Tomato, Black-eyed Susan, Peach, Sweet Corn, and Crab Apple. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.

Which hardiness zone is Cobb Island, really?

Officially, Cobb Island sits in USDA zones 6a-7b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.

Is the soil safe to grow vegetables in Cobb Island?

The federal record around Cobb Island is a meaningful one — 206 documented sites — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.

How do I protect my plants from frost in Cobb Island?

As the season closes around the first 28°F hard freeze near Dec 15 (NOAA 1991–2020 climate normals), a few moves buy time: cover tender plants with floating row cover or an old sheet on still, clear nights, water the soil the afternoon before a freeze so it holds warmth overnight, and harvest frost-tender crops like tomatoes, peppers, and basil before the first hard night. Hardy greens and root crops shrug off light frost and often sweeten after it, so leave them in.

Everything on this page is a Cobb Island average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.