Keene, NH planting zone & frost dates
Keene is in USDA hardiness zone 5b. The last spring frost usually comes around May 14 and the first fall frost around October 1, for a growing season of about 138 days.
Planting calendar for Keene
Dates are counted from the average last spring frost (May 14) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Mar 19 – Apr 2 Transplant outdoors: May 21 – May 28 |
| Peppers | Start seeds indoors: Mar 5 – Mar 19 Transplant outdoors: May 28 – Jun 4 |
| Eggplant | Start seeds indoors: Mar 5 – Mar 19 Transplant outdoors: May 28 – Jun 4 |
| Broccoli | Start seeds indoors: Mar 5 – Mar 19 Transplant outdoors: Apr 16 – Apr 30 |
| Cabbage | Start seeds indoors: Mar 5 – Mar 19 Transplant outdoors: Apr 16 – Apr 30 |
| Onions (sets) | Plant outdoors: Apr 16 – Apr 30 |
| Peas | Sow outdoors: Apr 2 – Apr 16 |
| Spinach | Sow outdoors: Apr 2 – Apr 16 |
| Lettuce | Sow outdoors: Apr 16 – Apr 30 |
| Carrots | Sow outdoors: Apr 16 – Apr 30 |
| Potatoes | Plant outdoors: Apr 16 – Apr 30 |
| Beans | Sow outdoors: May 21 – May 28 |
| Sweet corn | Sow outdoors: May 21 – May 28 |
| Cucumbers | Sow outdoors: May 21 – May 28 |
| Squash & zucchini | Sow outdoors: May 21 – May 28 |
| Basil | Start seeds indoors: Apr 2 – Apr 16 Transplant outdoors: May 21 – May 28 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 6 (8 weeks before the average first fall frost on Oct 1).
Useful for zone 5b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Cold frame / mini greenhouse — adds weeks to a short season
As an Amazon Associate, FrostZoneMap earns from qualifying purchases, at no extra cost to you.
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 30 | May 14 | May 28 |
| First 32°F frost in fall is before | Oct 14 | Oct 1 | Sep 18 |
How to read it: in spring there is a 10% chance of a frost after May 28, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 18. A hard freeze (28°F) usually ends around May 2.
Hardiness zone by ZIP code in Keene
- 03431 zone 5b
- 03435 zone 5b
Nearby cities
- Claremont zone 5b, last frost May 14
- Lebanon zone 5a, last frost May 9
- Bedford zone 6a, last frost Apr 21
- Merrimack zone 6a, last frost Apr 30
- Concord zone 5b, last frost May 8
- East Concord zone 5b, last frost May 8
- Manchester zone 6a, last frost Apr 30
- Nashua zone 6a, last frost Apr 30
Questions
What growing zone is Keene, NH?
Keene is in USDA Plant Hardiness Zone 5b (average extreme winter low -15°F to -10°F), according to the USDA 2023 map.
When is the last frost in Keene?
The average last spring frost (32°F) in Keene is May 14. There is still a 10% chance of frost until May 28.
When can I plant tomatoes in Keene?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 21 – May 28. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Keene, NH (USC00274399), 3.8 km (2.4 mi) from the city center, elevation 156 m, based on 25 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.