Concord, CA planting zone & frost dates
Concord is in USDA hardiness zone 9b. The last spring frost usually comes around January 9 and the first fall frost around December 14, for a growing season of about 343 days.
Planting calendar for Concord
Dates are counted from the average last spring frost (January 9) 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: Nov 14 – Nov 28 Transplant outdoors: Jan 16 – Jan 23 |
| Peppers | Start seeds indoors: Oct 31 – Nov 14 Transplant outdoors: Jan 23 – Jan 30 |
| Eggplant | Start seeds indoors: Oct 31 – Nov 14 Transplant outdoors: Jan 23 – Jan 30 |
| Broccoli | Start seeds indoors: Oct 31 – Nov 14 Transplant outdoors: Dec 12 – Dec 26 |
| Cabbage | Start seeds indoors: Oct 31 – Nov 14 Transplant outdoors: Dec 12 – Dec 26 |
| Onions (sets) | Plant outdoors: Dec 12 – Dec 26 |
| Peas | Sow outdoors: Nov 28 – Dec 12 |
| Spinach | Sow outdoors: Nov 28 – Dec 12 |
| Lettuce | Sow outdoors: Dec 12 – Dec 26 |
| Carrots | Sow outdoors: Dec 12 – Dec 26 |
| Potatoes | Plant outdoors: Dec 12 – Dec 26 |
| Beans | Sow outdoors: Jan 16 – Jan 23 |
| Sweet corn | Sow outdoors: Jan 16 – Jan 23 |
| Cucumbers | Sow outdoors: Jan 16 – Jan 23 |
| Squash & zucchini | Sow outdoors: Jan 16 – Jan 23 |
| Basil | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Jan 16 – Jan 23 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 19 (8 weeks before the average first fall frost on Dec 14).
Useful for zone 9b 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
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Dec 16 | Jan 9 | Feb 12 |
| First 32°F frost in fall is before | Jan 16 | Dec 14 | Nov 28 |
How to read it: in spring there is a 10% chance of a frost after February 12, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 28. A hard freeze (28°F) usually ends around December 30.
Hardiness zone by ZIP code in Concord
- 94518 zone 9b
- 94519 zone 9b
- 94520 zone 9b
- 94521 zone 9b
- 94522 zone 9b
- 94524 zone 9b
- 94527 zone 9b
- 94529 zone 9b
Nearby cities
- Pleasant Hill zone 9b, last frost Jan 7
- Walnut Creek zone 9b, last frost Jan 7
- Bay Point zone 9b, last frost Jan 9
- Clayton zone 9b, last frost Jan 9
- Martinez zone 9b, last frost Feb 28
- Lafayette zone 9b, last frost Jan 7
- Alamo zone 9b, last frost Jan 7
- Benicia zone 9b, last frost Feb 28
Questions
What growing zone is Concord, CA?
Concord is in USDA Plant Hardiness Zone 9b (average extreme winter low 25°F to 30°F), according to the USDA 2023 map.
When is the last frost in Concord?
The average last spring frost (32°F) in Concord is January 9. There is still a 10% chance of frost until February 12.
When can I plant tomatoes in Concord?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jan 16 – Jan 23. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Concord Buchanan Fld, CA (USW00023254), 2.6 km (1.6 mi) from the city center, elevation 6 m, based on 17 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.