Harper, TX 76856 planting calendar
- USDA zone
- 8b15 to 20 °F
- Last frost
- Mar 18avg, 32°F
- First frost
- Nov 13avg, 32°F
- Growing season
- 241days
Harper, Texas is in USDA plant hardiness zone 8b. Its average last spring frost is around March 18 and the first fall frost around November 13, giving a growing season of about 241 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.
Harper planting calendar
Each crop's windows are counted from Harper'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 | Jan 21 – Feb 4 | Mar 25 – Apr 1 | May 24 – Jun 13 | — |
| Pepper | Very tender | Jan 7 – Jan 21 | Apr 1 – Apr 8 | May 31 – Jun 30 | — |
| Cucumber | Tender | Feb 18 – Feb 25 | Mar 25 – Apr 1 | May 14 – Jun 3 | — |
| Summer squash / zucchini | Tender | — | Mar 25 – Apr 1 | May 9 – May 24 | — |
| Bush bean | Tender | — | Mar 25 – Apr 1 | May 14 – May 24 | Sep 14 – Sep 24 |
| Sweet corn | Tender | — | Mar 18 – Apr 1 | May 17 – Jun 16 | — |
| Basil | Very tender | Feb 4 – Feb 18 | Mar 25 – Apr 1 | Apr 24 – May 9 | — |
| Lettuce | Half-hardy | Feb 4 – Feb 18 | Feb 18 – Mar 4 | Apr 4 – Apr 19 | Aug 31 – Sep 15 |
| Pea | Hardy | — | Feb 4 – Feb 18 | Mar 31 – Apr 15 | Aug 21 – Sep 5 |
| Spinach | Hardy | — | Feb 4 – Feb 18 | Mar 16 – Mar 26 | Sep 10 – Sep 20 |
| Carrot | Half-hardy | — | Feb 25 – Mar 4 | Apr 26 – May 16 | Aug 11 – Aug 31 |
| Broccoli | Half-hardy | Jan 21 – Feb 4 | Feb 18 – Mar 4 | Apr 14 – May 4 | Aug 16 – Sep 5 |
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 USC00415650. 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 3 | Apr 20 | Nov 4 | Nov 20 | 214 |
| 32°F (freeze) | Mar 18 | Apr 7 | Nov 13 | Dec 1 | 241 |
| 28°F | Mar 4 | Mar 22 | Nov 26 | Dec 17 | 268 |
| 24°F | Feb 18 | Mar 12 | Dec 10 | Jan 8 | 299 |
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) | 6,330 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 9,611 | cool-season crops (brassicas, greens) |
Hardiness zone 8b
Harper sits in USDA plant hardiness zone 8b on the 2023 map — meaning its average annual extreme minimum winter temperature is about 15 to 20 °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 8b, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Harper?
- Harper, Texas is in USDA plant hardiness zone 8b on the 2023 map (average annual extreme minimum temperature 15 to 20 °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 Harper?
- The average (median) last spring frost at 32°F is around March 18, 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 7, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Harper?
- The average first fall frost at 32°F is around November 13. That leaves a growing season of about 241 days between the average last spring and first fall frosts.
- When should I start tomatoes in Harper?
- Start tomato seeds indoors about Jan 21 – Feb 4 and transplant them outside about Mar 25 – Apr 1, once the danger of frost has passed. Estimated first harvest is around May 24 – Jun 13.
- How long is the growing season in Harper?
- About 241 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~March 18) and the average first fall frost (~November 13). 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 USC00415650 (Mason, 7.5 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.