Smithtown, NY planting zone & frost dates
Smithtown is in USDA hardiness zone 7b. The last spring frost usually comes around April 10 and the first fall frost around November 2, for a growing season of about 207 days.
Planting calendar for Smithtown
Dates are counted from the average last spring frost (April 10) 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 13 – Feb 27 Transplant outdoors: Apr 17 – Apr 24 |
| Peppers | Start seeds indoors: Jan 30 – Feb 13 Transplant outdoors: Apr 24 – May 1 |
| Eggplant | Start seeds indoors: Jan 30 – Feb 13 Transplant outdoors: Apr 24 – May 1 |
| Broccoli | Start seeds indoors: Jan 30 – Feb 13 Transplant outdoors: Mar 13 – Mar 27 |
| Cabbage | Start seeds indoors: Jan 30 – Feb 13 Transplant outdoors: Mar 13 – Mar 27 |
| Onions (sets) | Plant outdoors: Mar 13 – Mar 27 |
| Peas | Sow outdoors: Feb 27 – Mar 13 |
| Spinach | Sow outdoors: Feb 27 – Mar 13 |
| Lettuce | Sow outdoors: Mar 13 – Mar 27 |
| Carrots | Sow outdoors: Mar 13 – Mar 27 |
| Potatoes | Plant outdoors: Mar 13 – Mar 27 |
| Beans | Sow outdoors: Apr 17 – Apr 24 |
| Sweet corn | Sow outdoors: Apr 17 – Apr 24 |
| Cucumbers | Sow outdoors: Apr 17 – Apr 24 |
| Squash & zucchini | Sow outdoors: Apr 17 – Apr 24 |
| Basil | Start seeds indoors: Feb 27 – Mar 13 Transplant outdoors: Apr 17 – Apr 24 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 7 (8 weeks before the average first fall frost on Nov 2).
Useful for zone 7b 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 | Mar 31 | Apr 10 | Apr 25 |
| First 32°F frost in fall is before | Nov 15 | Nov 2 | Oct 18 |
How to read it: in spring there is a 10% chance of a frost after April 25, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 18. A hard freeze (28°F) usually ends around March 30.
Hardiness zone by ZIP code in Smithtown
- 11787 zone 7b
Nearby cities
- Hauppauge zone 7b, last frost Apr 10
- Nesconset zone 7b, last frost Apr 10
- Saint James zone 7b, last frost Apr 15
- Kings Park zone 7b, last frost Apr 9
- Central Islip zone 7b, last frost Apr 10
- Ronkonkoma zone 7b, last frost Apr 10
- Lake Ronkonkoma zone 7b, last frost Apr 10
- Lake Grove zone 7b, last frost Apr 10
Questions
What growing zone is Smithtown, NY?
Smithtown is in USDA Plant Hardiness Zone 7b (average extreme winter low 5°F to 10°F), according to the USDA 2023 map.
When is the last frost in Smithtown?
The average last spring frost (32°F) in Smithtown is April 10. There is still a 10% chance of frost until April 25.
When can I plant tomatoes in Smithtown?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 17 – Apr 24. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Islip Li Macarthur Ap, NY (USW00004781), 10.8 km (6.7 mi) from the city center, elevation 26 m, based on 30 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.