Blossburg, PA planting calendar
- USDA zone
- 6a−10 to −5 °F
- Last frost
- May 16avg, 32°F
- First frost
- Oct 2avg, 32°F
- Growing season
- 139days
Blossburg, Pennsylvania is in USDA plant hardiness zone 6a. Its average last spring frost is around May 16 and the first fall frost around October 2, giving a growing season of about 139 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.
Blossburg planting calendar
Each crop's windows are counted from Blossburg'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 | Mar 21 – Apr 4 | May 23 – May 30 | Jul 22 – Aug 11 | — |
| Pepper | Very tender | Mar 7 – Mar 21 | May 30 – Jun 6 | Jul 29 – Aug 28 | — |
| Cucumber | Tender | Apr 18 – Apr 25 | May 23 – May 30 | Jul 12 – Aug 1 | — |
| Summer squash / zucchini | Tender | — | May 23 – May 30 | Jul 7 – Jul 22 | — |
| Bush bean | Tender | — | May 23 – May 30 | Jul 12 – Jul 22 | Aug 3 – Aug 13 |
| Sweet corn | Tender | — | May 16 – May 30 | Jul 15 – Aug 14 | — |
| Basil | Very tender | Apr 4 – Apr 18 | May 23 – May 30 | Jun 22 – Jul 7 | — |
| Lettuce | Half-hardy | Apr 4 – Apr 18 | Apr 18 – May 2 | Jun 2 – Jun 17 | Jul 20 – Aug 4 |
| Pea | Hardy | — | Apr 4 – Apr 18 | May 29 – Jun 13 | Jul 10 – Jul 25 |
| Spinach | Hardy | — | Apr 4 – Apr 18 | May 14 – May 24 | Jul 30 – Aug 9 |
| Carrot | Half-hardy | — | Apr 25 – May 2 | Jun 24 – Jul 14 | Jun 30 – Jul 20 |
| Broccoli | Half-hardy | Mar 21 – Apr 4 | Apr 18 – May 2 | Jun 12 – Jul 2 | Jul 5 – Jul 25 |
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 USC00361212. 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 | May 29 | Jun 11 | Sep 22 | Oct 4 | 115 |
| 32°F (freeze) | May 16 | May 29 | Oct 2 | Oct 16 | 139 |
| 28°F | May 1 | May 19 | Oct 13 | Oct 31 | 163 |
| 24°F | Apr 20 | May 5 | Oct 28 | Nov 10 | 189 |
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) | 2,272 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 4,258 | cool-season crops (brassicas, greens) |
Hardiness zone 6a
Blossburg sits in USDA plant hardiness zone 6a on the 2023 map — meaning its average annual extreme minimum winter temperature is about −10 to −5 °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 6a, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Blossburg?
- Blossburg, Pennsylvania is in USDA plant hardiness zone 6a on the 2023 map (average annual extreme minimum temperature −10 to −5 °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 Blossburg?
- The average (median) last spring frost at 32°F is around May 16, from NOAA's 1991–2020 climate normals at the nearest reporting station. Roughly one year in ten the last frost is as late as May 29, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Blossburg?
- The average first fall frost at 32°F is around October 2. That leaves a growing season of about 139 days between the average last spring and first fall frosts.
- When should I start tomatoes in Blossburg?
- Start tomato seeds indoors about Mar 21 – Apr 4 and transplant them outside about May 23 – May 30, once the danger of frost has passed. Estimated first harvest is around Jul 22 – Aug 11.
- How long is the growing season in Blossburg?
- About 139 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~May 16) and the average first fall frost (~October 2). 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 USC00361212 (Canton, 4.1 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.