Calvert, KY planting calendar
- USDA zone
- 7a0 to 5 °F
- Last frost
- Apr 3avg, 32°F
- First frost
- Oct 30avg, 32°F
- Growing season
- 207days
Calvert, Kentucky is in USDA plant hardiness zone 7a. Its average last spring frost is around April 3 and the first fall frost around October 30, giving a growing season of about 207 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.
Calvert planting calendar
Each crop's windows are counted from Calvert'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 6 – Feb 20 | Apr 10 – Apr 17 | Jun 9 – Jun 29 | — |
| Pepper | Very tender | Jan 23 – Feb 6 | Apr 17 – Apr 24 | Jun 16 – Jul 16 | — |
| Cucumber | Tender | Mar 6 – Mar 13 | Apr 10 – Apr 17 | May 30 – Jun 19 | — |
| Summer squash / zucchini | Tender | — | Apr 10 – Apr 17 | May 25 – Jun 9 | — |
| Bush bean | Tender | — | Apr 10 – Apr 17 | May 30 – Jun 9 | Aug 31 – Sep 10 |
| Sweet corn | Tender | — | Apr 3 – Apr 17 | Jun 2 – Jul 2 | — |
| Basil | Very tender | Feb 20 – Mar 6 | Apr 10 – Apr 17 | May 10 – May 25 | — |
| Lettuce | Half-hardy | Feb 20 – Mar 6 | Mar 6 – Mar 20 | Apr 20 – May 5 | Aug 17 – Sep 1 |
| Pea | Hardy | — | Feb 20 – Mar 6 | Apr 16 – May 1 | Aug 7 – Aug 22 |
| Spinach | Hardy | — | Feb 20 – Mar 6 | Apr 1 – Apr 11 | Aug 27 – Sep 6 |
| Carrot | Half-hardy | — | Mar 13 – Mar 20 | May 12 – Jun 1 | Jul 28 – Aug 17 |
| Broccoli | Half-hardy | Feb 6 – Feb 20 | Mar 6 – Mar 20 | Apr 30 – May 20 | Aug 2 – Aug 22 |
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 USC00118020. 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 16 | May 2 | Oct 21 | Nov 1 | 188 |
| 32°F (freeze) | Apr 3 | Apr 21 | Oct 30 | Nov 12 | 207 |
| 28°F | Mar 23 | Apr 9 | Nov 8 | Nov 25 | 230 |
| 24°F | Mar 12 | Mar 30 | Nov 19 | Dec 7 | 253 |
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) | 4,329 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 6,948 | cool-season crops (brassicas, greens) |
Hardiness zone 7a
Calvert 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 Calvert?
- Calvert, Kentucky 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 Calvert?
- The average (median) last spring frost at 32°F is around April 3, 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 21, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Calvert?
- The average first fall frost at 32°F is around October 30. That leaves a growing season of about 207 days between the average last spring and first fall frosts.
- When should I start tomatoes in Calvert?
- Start tomato seeds indoors about Feb 6 – Feb 20 and transplant them outside about Apr 10 – Apr 17, once the danger of frost has passed. Estimated first harvest is around Jun 9 – Jun 29.
- How long is the growing season in Calvert?
- About 207 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~April 3) and the average first fall frost (~October 30). 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 USC00118020 (Smithland L&d, 8.6 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.