Milton, MA planting zone & frost dates
Milton is in USDA hardiness zone 6b. The last spring frost usually comes around April 18 and the first fall frost around October 26, for a growing season of about 190 days.
Planting calendar for Milton
Dates are counted from the average last spring frost (April 18) 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 21 – Mar 7 Transplant outdoors: Apr 25 – May 2 |
| Peppers | Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: May 2 – May 9 |
| Eggplant | Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: May 2 – May 9 |
| Broccoli | Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: Mar 21 – Apr 4 |
| Cabbage | Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: Mar 21 – Apr 4 |
| Onions (sets) | Plant outdoors: Mar 21 – Apr 4 |
| Peas | Sow outdoors: Mar 7 – Mar 21 |
| Spinach | Sow outdoors: Mar 7 – Mar 21 |
| Lettuce | Sow outdoors: Mar 21 – Apr 4 |
| Carrots | Sow outdoors: Mar 21 – Apr 4 |
| Potatoes | Plant outdoors: Mar 21 – Apr 4 |
| Beans | Sow outdoors: Apr 25 – May 2 |
| Sweet corn | Sow outdoors: Apr 25 – May 2 |
| Cucumbers | Sow outdoors: Apr 25 – May 2 |
| Squash & zucchini | Sow outdoors: Apr 25 – May 2 |
| Basil | Start seeds indoors: Mar 7 – Mar 21 Transplant outdoors: Apr 25 – May 2 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 31 (8 weeks before the average first fall frost on Oct 26).
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 7 | Apr 18 | Apr 30 |
| First 32°F frost in fall is before | Nov 8 | Oct 26 | Oct 9 |
How to read it: in spring there is a 10% chance of a frost after April 30, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 9. A hard freeze (28°F) usually ends around April 6.
Hardiness zone by ZIP code in Milton
- 02186 zone 6b
Nearby cities
- Mattapan zone 6b, last frost Apr 19
- Ashmont zone 6b, last frost Apr 19
- Dorchester zone 6b, last frost Apr 19
- Hyde Park zone 6b, last frost Apr 18
- Quincy zone 7a, last frost Apr 25
- Roslindale zone 6b, last frost Apr 19
- Braintree zone 6b, last frost Apr 25
- Roxbury Crossing zone 7a, last frost Apr 19
Questions
What growing zone is Milton, MA?
Milton is in USDA Plant Hardiness Zone 6b (average extreme winter low -5°F to 0°F), according to the USDA 2023 map.
When is the last frost in Milton?
The average last spring frost (32°F) in Milton is April 18. There is still a 10% chance of frost until April 30.
When can I plant tomatoes in Milton?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 25 – May 2. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Blue Hill Coop, MA (USC00190736), 5.7 km (3.5 mi) from the city center, elevation 190 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.