Frederick, MD 21705 planting calendar
- USDA zone
- 7b5 to 10 °F
- Last frost
- Apr 2avg, 32°F
- First frost
- Nov 6avg, 32°F
- Growing season
- 218days
Frederick, Maryland is in USDA plant hardiness zone 7b. Its average last spring frost is around April 2 and the first fall frost around November 6, giving a growing season of about 218 days (NOAA 1991–2020 normals, 32°F, median). Start tender crops like tomatoes and peppers indoors weeks before the last frost and set them out afterward; sow hardy crops such as peas, spinach, and lettuce before it. The planner below turns those frost dates into a printable per-crop planting calendar.
Frederick planting calendar
Each crop's windows are counted from Frederick's average frost dates. 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.
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting |
|---|---|---|---|---|---|
| Tomato | Tender | Feb 5 – Feb 19 | Apr 9 – Apr 16 | Jun 8 – Jun 28 | — |
| Pepper | Very tender | Jan 22 – Feb 5 | Apr 16 – Apr 23 | Jun 15 – Jul 15 | — |
| Cucumber | Tender | Mar 5 – Mar 12 | Apr 9 – Apr 16 | May 29 – Jun 18 | — |
| Summer squash / zucchini | Tender | — | Apr 9 – Apr 16 | May 24 – Jun 8 | — |
| Bush bean | Tender | — | Apr 9 – Apr 16 | May 29 – Jun 8 | Sep 7 – Sep 17 |
| Sweet corn | Tender | — | Apr 2 – Apr 16 | Jun 1 – Jul 1 | — |
| Basil | Very tender | Feb 19 – Mar 5 | Apr 9 – Apr 16 | May 9 – May 24 | — |
| Lettuce | Half-hardy | Feb 19 – Mar 5 | Mar 5 – Mar 19 | Apr 19 – May 4 | Aug 24 – Sep 8 |
| Pea | Hardy | — | Feb 19 – Mar 5 | Apr 15 – Apr 30 | Aug 14 – Aug 29 |
| Spinach | Hardy | — | Feb 19 – Mar 5 | Mar 31 – Apr 10 | Sep 3 – Sep 13 |
| Carrot | Half-hardy | — | Mar 12 – Mar 19 | May 11 – May 31 | Aug 4 – Aug 24 |
| Broccoli | Half-hardy | Feb 5 – Feb 19 | Mar 5 – Mar 19 | Apr 29 – May 19 | Aug 9 – Aug 29 |
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.
Frost & freeze dates
From NOAA's 1991–2020 Climate Normals at station USC00183348. 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 (p10 for spring, p90 for fall) — 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 15 | May 2 | Oct 24 | Nov 6 | 193 |
| 32°F (freeze) | Apr 2 | Apr 15 | Nov 6 | Nov 24 | 218 |
| 28°F | Mar 21 | Apr 4 | Nov 21 | Dec 11 | 245 |
| 24°F | Mar 9 | Mar 26 | Dec 7 | Dec 28 | 272 |
32°F is the standard "freeze" line that damages tender crops; lighter 36°F frost can nip the most cold-sensitive plants, while hardy crops shrug off light frost down toward 28°F. Use the threshold that matches what you are protecting.
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. Warm-season crops need a long, warm GDD total; a short, cool GDD total favors greens and brassicas.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 4,174 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 6,775 | cool-season crops (brassicas, greens) |
Hardiness zone 7b
Frederick sits in USDA plant hardiness zone 7b on the 2023 map — meaning its average annual extreme minimum winter temperature is about 5 to 10 °F. That number 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.
Explore more places in zone 7b, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Frederick?
- Frederick, Maryland is in USDA plant hardiness zone 7b on the 2023 map (average annual extreme minimum temperature 5 to 10 °F) — from the USDA Plant Hardiness Zone Map 2023, matched to this location's ZIP. See the methodology page for sources.
- When is the last frost in Frederick?
- The average (median) last spring frost at 32°F is around April 2, from NOAA's 1991–2020 climate normals at the nearest reporting station. Roughly one year in ten the last frost is as late as April 15, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Frederick?
- The average first fall frost at 32°F is around November 6. That leaves a growing season of about 218 days between the average last spring and first fall frosts.
- When should I start tomatoes in Frederick?
- Start tomato seeds indoors about Feb 5 – Feb 19 and transplant them outside about Apr 9 – Apr 16, once the danger of frost has passed. Estimated first harvest is around Jun 8 – Jun 28.
- How long is the growing season in Frederick?
- About 218 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~April 2) and the average first fall frost (~November 6). Cold-hardy crops extend usable time at both ends; frost-tender crops fit inside it.
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020 for station USC00183348 (Frederick Police Brks, 2.6 km away). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to this 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.