Trenton, NJ planting zone & frost dates
Trenton is in USDA hardiness zone 7a. The last spring frost usually comes around April 17 and the first fall frost around October 28, for a growing season of about 192 days.
Planting calendar for Trenton
Dates are counted from the average last spring frost (April 17) 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: Feb 20 – Mar 6 Transplant outdoors: Apr 24 – May 1 |
| Peppers | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: May 1 – May 8 |
| Eggplant | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: May 1 – May 8 |
| Broccoli | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: Mar 20 – Apr 3 |
| Cabbage | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: Mar 20 – Apr 3 |
| Onions (sets) | Plant outdoors: Mar 20 – Apr 3 |
| Peas | Sow outdoors: Mar 6 – Mar 20 |
| Spinach | Sow outdoors: Mar 6 – Mar 20 |
| Lettuce | Sow outdoors: Mar 20 – Apr 3 |
| Carrots | Sow outdoors: Mar 20 – Apr 3 |
| Potatoes | Plant outdoors: Mar 20 – Apr 3 |
| Beans | Sow outdoors: Apr 24 – May 1 |
| Sweet corn | Sow outdoors: Apr 24 – May 1 |
| Cucumbers | Sow outdoors: Apr 24 – May 1 |
| Squash & zucchini | Sow outdoors: Apr 24 – May 1 |
| Basil | Start seeds indoors: Mar 6 – Mar 20 Transplant outdoors: Apr 24 – May 1 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 2 (8 weeks before the average first fall frost on Oct 28).
Useful for zone 7a 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
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 2 | Apr 17 | May 6 |
| First 32°F frost in fall is before | Nov 10 | Oct 28 | Oct 11 |
How to read it: in spring there is a 10% chance of a frost after May 6, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 11. A hard freeze (28°F) usually ends around April 2.
Hardiness zone by ZIP code in Trenton
- 08601 zone 7a
- 08602 zone 7a
- 08603 zone 7a
- 08604 zone 7a
- 08605 zone 7a
- 08606 zone 7a
- 08607 zone 7a
- 08609 zone 7a
- 08610 zone 7a
- 08611 zone 7a
- 08618 zone 7b
- 08619 zone 7a
- 08620 zone 7a
- 08625 zone 7a
- 08628 zone 7b
- 08629 zone 7a
- 08638 zone 7a
- 08645 zone 7a
- 08646 zone 7a
- 08647 zone 7a
- 08650 zone 7a
- 08666 zone 7a
- 08690 zone 7a
- 08691 zone 7a
- 08695 zone 7a
Nearby cities
- Mercerville zone 7a, last frost Apr 17
- Mercerville-Hamilton Square zone 7a, last frost Apr 25
- Ewing zone 7b, last frost Apr 17
- Hamilton Square zone 7a, last frost Apr 25
- Princeton zone 7a, last frost Apr 25
- Princeton Meadows zone 7a, last frost Apr 25
- Willingboro zone 7b, last frost Apr 15
- Mount Holly zone 7b, last frost Apr 15
Questions
What growing zone is Trenton, NJ?
Trenton is in USDA Plant Hardiness Zone 7a (average extreme winter low 0°F to 5°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 7b.
When is the last frost in Trenton?
The average last spring frost (32°F) in Trenton is April 17. There is still a 10% chance of frost until May 6.
When can I plant tomatoes in Trenton?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 24 – May 1. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Trenton State College, NJ (USC00288880), 7.3 km (4.5 mi) from the city center, elevation 30 m, based on 11 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.