USDA zone 7a in Maryland
USDA plant hardiness zone 7a covers 13 locations across Maryland (average annual extreme minimum 0 to 5 °F): Bel Air South, MD, Bowie, MD, Brunswick, MD, Cockeysville, MD, Cumberland, MD, Eldersburg, MD, and 7 more. Average last spring frost across this group ranges April 2 (Frederick) to April 29 (Luke), and growing seasons run 174–220 days (Luke to Randallstown) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Maryland location's own frost dates; the printable planting calendar uses Highfield-Cascade, this group's median-season location.
- USDA zone
- 7a0 to 5 °F
- Last frost range
- Apr 2–Apr 29avg, 32°F
- First frost range
- Oct 18–Nov 7avg, 32°F
- Growing season range
- 174–220days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Bel Air South | Jarrettsville, Pylesville, Port Deposit, Darlington, Delta | Conowingo Dam | Apr 3 | Nov 6 | 217 |
| Bowie | — | Beltsville | Apr 10 | Nov 1 | 202 |
| Brunswick | Boonsboro, Middletown, Fairplay, Garretts Mill, Burkittsville, Bolivar, +4 more | Sharpsburg 5 S | Apr 26 | Oct 18 | 175 |
| Cockeysville | Jarrettsville, Westminster, Reisterstown, Hampstead, Manchester, New Freedom, +6 more | Millers 4 Ne | Apr 19 | Oct 25 | 188 |
| Cumberland | Fort Ashby, Wiley Ford, Green Spring, Ellerslie, Spring Gap, Flintstone, +2 more | Cumberland 2 | Apr 15 | Oct 24 | 190 |
| Eldersburg | Green Valley, Linganore, Urbana, Ten Mile Creek, Mount Airy, Bartonsville, +3 more | Damascus 3 Ssw | Apr 14 | Oct 29 | 196 |
| Elkton | North Star, St. Georges | Wilmington New Castle Co Ap | Apr 7 | Nov 1 | 209 |
| Frederick | — | Frederick Police Brks | Apr 2 | Nov 6 | 218 |
| Hagerstown | St. James, Maugansville, Leitersburg, Greencastle, Mercersburg, Funkstown, +2 more | Hagerstown Washington Co Ap | Apr 7 | Nov 4 | 209 |
| Highfield-Cascade * | Sabillasville, Smithsburg, Myersville | Catoctin Mtn Park | Apr 14 | Oct 30 | 197 |
| Luke | — | Savage Rvr Dam | Apr 29 | Oct 20 | 174 |
| Randallstown | Owings Mills, Reisterstown | Cylburn | Apr 2 | Nov 7 | 220 |
| Westminster | Parkville, Littlestown, New Oxford | Hanover 4 Sw | Apr 24 | Oct 20 | 177 |
* Highfield-Cascade is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Highfield-Cascade, representative)
Computed from Highfield-Cascade's average frost dates — the median-season location in this Marylandzone 7a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Feb 17 – Mar 3 | Apr 21 – Apr 28 | Jun 20 – Jul 10 | — | matures comfortably |
| Pepper | Very tender | Feb 3 – Feb 17 | Apr 28 – May 5 | Jun 27 – Jul 27 | — | matures comfortably |
| Cucumber | Tender | Mar 17 – Mar 24 | Apr 21 – Apr 28 | Jun 10 – Jun 30 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 21 – Apr 28 | Jun 5 – Jun 20 | — | matures comfortably |
| Bush bean | Tender | — | Apr 21 – Apr 28 | Jun 10 – Jun 20 | Aug 31 – Sep 10 | matures comfortably |
| Sweet corn | Tender | — | Apr 14 – Apr 28 | Jun 13 – Jul 13 | — | matures comfortably |
| Basil | Very tender | Mar 3 – Mar 17 | Apr 21 – Apr 28 | May 21 – Jun 5 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 3 – Mar 17 | Mar 17 – Mar 31 | May 1 – May 16 | Aug 17 – Sep 1 | matures comfortably |
| Pea | Hardy | — | Mar 3 – Mar 17 | Apr 27 – May 12 | Aug 7 – Aug 22 | matures comfortably |
| Spinach | Hardy | — | Mar 3 – Mar 17 | Apr 12 – Apr 22 | Aug 27 – Sep 6 | matures comfortably |
| Carrot | Half-hardy | — | Mar 24 – Mar 31 | May 23 – Jun 12 | Jul 28 – Aug 17 | matures comfortably |
| Broccoli | Half-hardy | Feb 17 – Mar 3 | Mar 17 – Mar 31 | May 11 – May 31 | Aug 2 – Aug 22 | matures comfortably |
Which crops fit this growing season
Using Highfield-Cascade's own 197-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Highfield-Cascade)
From NOAA's 1991–2020 Climate Normals at station USC00181530. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Apr 27 | May 12 | Oct 20 | Nov 1 | 175 |
| 32°F (freeze) | Apr 14 | Apr 30 | Oct 30 | Nov 11 | 197 |
| 28°F | Apr 4 | Apr 17 | Nov 8 | Nov 26 | 218 |
| 24°F | Mar 26 | Apr 7 | Nov 20 | Dec 11 | 239 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 13 locations is 3,554; Highfield-Cascade's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 3,429 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 5,842 | cool-season crops (brassicas, greens) |
Hardiness zone 7a in Maryland
Zone 7a means an average annual extreme minimum winter temperature of about 0 to 5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Maryland spans 5 hardiness zones in this dataset — see all Maryland locations for the full range, including zones6a, 6b, 7b, 8a.
Explore zone 7a in other states at zone 7a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 7a mean in Maryland?
- Zone 7a means an average annual extreme minimum winter temperature of 0 to 5 °F — the standard USDA measure of which perennials survive winter. 13 locations in Maryland fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Maryland's zone 7a is the growing season longest?
- Randallstown runs the longest season on this page at about 220 days; Luke is shortest at about 174 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Maryland's zone 7a?
- Using Highfield-Cascade's frost dates (this page's median-season location): start seeds indoors about Feb 17 – Mar 3, then transplant outside about Apr 21 – Apr 28. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Maryland's zone 7a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 13 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.