Brian Head, UT planting calendar
- USDA zone
- 6a−10 to −5 °F
- Last frost
- Jun 21avg, 32°F
- First frost
- Sep 12avg, 32°F
- Growing season
- 82days
Brian Head, Utah is in USDA plant hardiness zone 6a. Its average last spring frost is around June 21 and the first fall frost around September 12, giving a growing season of about 82 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.
Brian Head planting calendar
Each crop's windows are counted from Brian Head'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 | Apr 26 – May 10 | Jun 28 – Jul 5 | Aug 27 – Sep 16 | — |
| Pepper | Very tender | Apr 12 – Apr 26 | Jul 5 – Jul 12 | Sep 3 – Oct 3 | — |
| Cucumber | Tender | May 24 – May 31 | Jun 28 – Jul 5 | Aug 17 – Sep 6 | — |
| Summer squash / zucchini | Tender | — | Jun 28 – Jul 5 | Aug 12 – Aug 27 | — |
| Bush bean | Tender | — | Jun 28 – Jul 5 | Aug 17 – Aug 27 | Jul 14 – Jul 24 |
| Sweet corn | Tender | — | Jun 21 – Jul 5 | Aug 20 – Sep 19 | — |
| Basil | Very tender | May 10 – May 24 | Jun 28 – Jul 5 | Jul 28 – Aug 12 | — |
| Lettuce | Half-hardy | May 10 – May 24 | May 24 – Jun 7 | Jul 8 – Jul 23 | Jun 30 – Jul 15 |
| Pea | Hardy | — | May 10 – May 24 | Jul 4 – Jul 19 | Jun 20 – Jul 5 |
| Spinach | Hardy | — | May 10 – May 24 | Jun 19 – Jun 29 | Jul 10 – Jul 20 |
| Carrot | Half-hardy | — | May 31 – Jun 7 | Jul 30 – Aug 19 | Jun 10 – Jun 30 |
| Broccoli | Half-hardy | Apr 26 – May 10 | May 24 – Jun 7 | Jul 18 – Aug 7 | Jun 15 – Jul 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 USC00420900. 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 | — | — | — | — | 53 |
| 32°F (freeze) | Jun 21 | Jul 6 | Sep 12 | Sep 23 | 82 |
| 28°F | Jun 7 | Jun 24 | Sep 22 | Oct 1 | 103 |
| 24°F | May 28 | Jun 13 | Oct 1 | Oct 12 | 125 |
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) | 549 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 1,761 | cool-season crops (brassicas, greens) |
Hardiness zone 6a
Brian Head 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 Brian Head?
- Brian Head, Utah 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 Brian Head?
- The average (median) last spring frost at 32°F is around June 21, from NOAA's 1991–2020 climate normals at the nearest reporting station. Roughly one year in ten the last frost is as late as July 6, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Brian Head?
- The average first fall frost at 32°F is around September 12. That leaves a growing season of about 82 days between the average last spring and first fall frosts.
- When should I start tomatoes in Brian Head?
- Start tomato seeds indoors about Apr 26 – May 10 and transplant them outside about Jun 28 – Jul 5, once the danger of frost has passed. Estimated first harvest is around Aug 27 – Sep 16.
- How long is the growing season in Brian Head?
- About 82 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~June 21) and the average first fall frost (~September 12). 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 USC00420900 (Brian Head, 6.8 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.