Portland, TN planting zone & frost dates
Portland is in USDA hardiness zone 7b. The last spring frost usually comes around April 5 and the first fall frost around November 1, for a growing season of about 210 days.
Planting calendar for Portland
Dates are counted from the average last spring frost (April 5) 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 8 – Feb 22 Transplant outdoors: Apr 12 – Apr 19 |
| Peppers | Start seeds indoors: Jan 25 – Feb 8 Transplant outdoors: Apr 19 – Apr 26 |
| Eggplant | Start seeds indoors: Jan 25 – Feb 8 Transplant outdoors: Apr 19 – Apr 26 |
| Broccoli | Start seeds indoors: Jan 25 – Feb 8 Transplant outdoors: Mar 8 – Mar 22 |
| Cabbage | Start seeds indoors: Jan 25 – Feb 8 Transplant outdoors: Mar 8 – Mar 22 |
| Onions (sets) | Plant outdoors: Mar 8 – Mar 22 |
| Peas | Sow outdoors: Feb 22 – Mar 8 |
| Spinach | Sow outdoors: Feb 22 – Mar 8 |
| Lettuce | Sow outdoors: Mar 8 – Mar 22 |
| Carrots | Sow outdoors: Mar 8 – Mar 22 |
| Potatoes | Plant outdoors: Mar 8 – Mar 22 |
| Beans | Sow outdoors: Apr 12 – Apr 19 |
| Sweet corn | Sow outdoors: Apr 12 – Apr 19 |
| Cucumbers | Sow outdoors: Apr 12 – Apr 19 |
| Squash & zucchini | Sow outdoors: Apr 12 – Apr 19 |
| Basil | Start seeds indoors: Feb 22 – Mar 8 Transplant outdoors: Apr 12 – Apr 19 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 6 (8 weeks before the average first fall frost on Nov 1).
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 21 | Apr 5 | Apr 19 |
| First 32°F frost in fall is before | Nov 14 | Nov 1 | Oct 21 |
How to read it: in spring there is a 10% chance of a frost after April 19, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 21. A hard freeze (28°F) usually ends around March 26.
Hardiness zone by ZIP code in Portland
- 37148 zone 7b
Nearby cities
- White House zone 7a, last frost Apr 7
- Gallatin zone 7b, last frost Apr 16
- Hendersonville zone 7b, last frost Apr 11
- Goodlettsville zone 7b, last frost Apr 11
- Springfield zone 7a, last frost Apr 9
- Mount Juliet zone 7b, last frost Apr 1
- Hermitage zone 7b, last frost Apr 1
- Lebanon zone 7b, last frost Apr 6
Questions
What growing zone is Portland, TN?
Portland 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 Portland?
The average last spring frost (32°F) in Portland is April 5. There is still a 10% chance of frost until April 19.
When can I plant tomatoes in Portland?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 12 – Apr 19. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Portland Sewage Plt, TN (USC00407359), 1.1 km (0.7 mi) from the city center, elevation 242 m, based on 27 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.