Reading, PA planting calendar
- USDA zone
- 7a0 to 5 °F
- Last frost
- Apr 14avg, 32°F
- First frost
- Oct 29avg, 32°F
- Growing season
- 197days
Reading, Pennsylvania is in USDA plant hardiness zone 7a. Its average last spring frost is around April 14 and the first fall frost around October 29, giving a growing season of about 197 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.
Reading planting calendar
Each crop's windows are counted from Reading'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 17 – Mar 3 | Apr 21 – Apr 28 | Jun 20 – Jul 10 | — |
| Pepper | Very tender | Feb 3 – Feb 17 | Apr 28 – May 5 | Jun 27 – Jul 27 | — |
| Cucumber | Tender | Mar 17 – Mar 24 | Apr 21 – Apr 28 | Jun 10 – Jun 30 | — |
| Summer squash / zucchini | Tender | — | Apr 21 – Apr 28 | Jun 5 – Jun 20 | — |
| Bush bean | Tender | — | Apr 21 – Apr 28 | Jun 10 – Jun 20 | Aug 30 – Sep 9 |
| Sweet corn | Tender | — | Apr 14 – Apr 28 | Jun 13 – Jul 13 | — |
| Basil | Very tender | Mar 3 – Mar 17 | Apr 21 – Apr 28 | May 21 – Jun 5 | — |
| Lettuce | Half-hardy | Mar 3 – Mar 17 | Mar 17 – Mar 31 | May 1 – May 16 | Aug 16 – Aug 31 |
| Pea | Hardy | — | Mar 3 – Mar 17 | Apr 27 – May 12 | Aug 6 – Aug 21 |
| Spinach | Hardy | — | Mar 3 – Mar 17 | Apr 12 – Apr 22 | Aug 26 – Sep 5 |
| Carrot | Half-hardy | — | Mar 24 – Mar 31 | May 23 – Jun 12 | Jul 27 – Aug 16 |
| Broccoli | Half-hardy | Feb 17 – Mar 3 | Mar 17 – Mar 31 | May 11 – May 31 | Aug 1 – Aug 21 |
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 USW00014712. 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 28 | May 13 | Oct 17 | Nov 1 | 172 |
| 32°F (freeze) | Apr 14 | Apr 30 | Oct 29 | Nov 10 | 197 |
| 28°F | Apr 1 | Apr 15 | Nov 8 | Nov 24 | 221 |
| 24°F | Mar 21 | Apr 3 | Nov 21 | Dec 8 | 244 |
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) | 3,538 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 5,918 | cool-season crops (brassicas, greens) |
Hardiness zone 7a
Reading sits in USDA plant hardiness zone 7a on the 2023 map — meaning its average annual extreme minimum winter temperature is about 0 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 7a, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Reading?
- Reading, Pennsylvania is in USDA plant hardiness zone 7a on the 2023 map (average annual extreme minimum temperature 0 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 Reading?
- The average (median) last spring frost at 32°F is around April 14, 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 30, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Reading?
- The average first fall frost at 32°F is around October 29. That leaves a growing season of about 197 days between the average last spring and first fall frosts.
- When should I start tomatoes in Reading?
- Start tomato seeds indoors about Feb 17 – Mar 3 and transplant them outside about Apr 21 – Apr 28, once the danger of frost has passed. Estimated first harvest is around Jun 20 – Jul 10.
- How long is the growing season in Reading?
- About 197 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~April 14) and the average first fall frost (~October 29). 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 USW00014712 (Reading Spaatz Fld, 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.