Union, NJ planting zone & frost dates
Union is in USDA hardiness zone 7a. The last spring frost usually comes around April 11 and the first fall frost around October 31, for a growing season of about 202 days.
Planting calendar for Union
Dates are counted from the average last spring frost (April 11) 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 14 – Feb 28 Transplant outdoors: Apr 18 – Apr 25 |
| Peppers | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Apr 25 – May 2 |
| Eggplant | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Apr 25 – May 2 |
| Broccoli | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Mar 14 – Mar 28 |
| Cabbage | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Mar 14 – Mar 28 |
| Onions (sets) | Plant outdoors: Mar 14 – Mar 28 |
| Peas | Sow outdoors: Feb 28 – Mar 14 |
| Spinach | Sow outdoors: Feb 28 – Mar 14 |
| Lettuce | Sow outdoors: Mar 14 – Mar 28 |
| Carrots | Sow outdoors: Mar 14 – Mar 28 |
| Potatoes | Plant outdoors: Mar 14 – Mar 28 |
| Beans | Sow outdoors: Apr 18 – Apr 25 |
| Sweet corn | Sow outdoors: Apr 18 – Apr 25 |
| Cucumbers | Sow outdoors: Apr 18 – Apr 25 |
| Squash & zucchini | Sow outdoors: Apr 18 – Apr 25 |
| Basil | Start seeds indoors: Feb 28 – Mar 14 Transplant outdoors: Apr 18 – Apr 25 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 5 (8 weeks before the average first fall frost on Oct 31).
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 30 | Apr 11 | Apr 28 |
| First 32°F frost in fall is before | Nov 15 | Oct 31 | Oct 14 |
How to read it: in spring there is a 10% chance of a frost after April 28, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 14. A hard freeze (28°F) usually ends around March 30.
Hardiness zone by ZIP code in Union
- 07083 zone 7a
Nearby cities
- Roselle Park zone 7b, last frost Apr 11
- Hillside zone 7b, last frost Apr 2
- Maplewood zone 7a, last frost Apr 18
- Irvington zone 7b, last frost Apr 4
- Roselle zone 7b, last frost Apr 11
- Millburn zone 7a, last frost Apr 18
- South Orange zone 7a, last frost Apr 18
- Cranford zone 7a, last frost Apr 11
Questions
What growing zone is Union, NJ?
Union is in USDA Plant Hardiness Zone 7a (average extreme winter low 0°F to 5°F), according to the USDA 2023 map.
When is the last frost in Union?
The average last spring frost (32°F) in Union is April 11. There is still a 10% chance of frost until April 28.
When can I plant tomatoes in Union?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 18 – Apr 25. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Cranford, NJ (USC00282023), 6.1 km (3.8 mi) from the city center, elevation 24 m, based on 18 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.