Hollis, OK planting calendar
- USDA zone
- 7b5 to 10 °F
- Last frost
- Apr 10avg, 32°F
- First frost
- Oct 28avg, 32°F
- Growing season
- 200days
Hollis, Oklahoma is in USDA plant hardiness zone 7b. Its average last spring frost is around April 10 and the first fall frost around October 28, giving a growing season of about 200 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.
Hollis planting calendar
Each crop's windows are counted from Hollis'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 13 – Feb 27 | Apr 17 – Apr 24 | Jun 16 – Jul 6 | — |
| Pepper | Very tender | Jan 30 – Feb 13 | Apr 24 – May 1 | Jun 23 – Jul 23 | — |
| Cucumber | Tender | Mar 13 – Mar 20 | Apr 17 – Apr 24 | Jun 6 – Jun 26 | — |
| Summer squash / zucchini | Tender | — | Apr 17 – Apr 24 | Jun 1 – Jun 16 | — |
| Bush bean | Tender | — | Apr 17 – Apr 24 | Jun 6 – Jun 16 | Aug 29 – Sep 8 |
| Sweet corn | Tender | — | Apr 10 – Apr 24 | Jun 9 – Jul 9 | — |
| Basil | Very tender | Feb 27 – Mar 13 | Apr 17 – Apr 24 | May 17 – Jun 1 | — |
| Lettuce | Half-hardy | Feb 27 – Mar 13 | Mar 13 – Mar 27 | Apr 27 – May 12 | Aug 15 – Aug 30 |
| Pea | Hardy | — | Feb 27 – Mar 13 | Apr 23 – May 8 | Aug 5 – Aug 20 |
| Spinach | Hardy | — | Feb 27 – Mar 13 | Apr 8 – Apr 18 | Aug 25 – Sep 4 |
| Carrot | Half-hardy | — | Mar 20 – Mar 27 | May 19 – Jun 8 | Jul 26 – Aug 15 |
| Broccoli | Half-hardy | Feb 13 – Feb 27 | Mar 13 – Mar 27 | May 7 – May 27 | Jul 31 – Aug 20 |
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 USC00344249. 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 20 | May 2 | Oct 21 | Oct 31 | 181 |
| 32°F (freeze) | Apr 10 | Apr 24 | Oct 28 | Nov 11 | 200 |
| 28°F | Mar 31 | Apr 14 | Nov 6 | Nov 21 | 219 |
| 24°F | Mar 19 | Apr 4 | Nov 15 | Dec 2 | 240 |
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) | 5,099 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 7,879 | cool-season crops (brassicas, greens) |
Hardiness zone 7b
Hollis 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 Hollis?
- Hollis, Oklahoma 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 Hollis?
- The average (median) last spring frost at 32°F is around April 10, 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 24, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Hollis?
- The average first fall frost at 32°F is around October 28. That leaves a growing season of about 200 days between the average last spring and first fall frosts.
- When should I start tomatoes in Hollis?
- Start tomato seeds indoors about Feb 13 – Feb 27 and transplant them outside about Apr 17 – Apr 24, once the danger of frost has passed. Estimated first harvest is around Jun 16 – Jul 6.
- How long is the growing season in Hollis?
- About 200 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~April 10) and the average first fall frost (~October 28). 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 USC00344249 (Hollis 5e, 5.9 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.