Waterbury, CT planting zone & frost dates
Waterbury is in USDA hardiness zone 6b. The last spring frost usually comes around April 26 and the first fall frost around October 16, for a growing season of about 175 days.
Planting calendar for Waterbury
Dates are counted from the average last spring frost (April 26) 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: Mar 1 – Mar 15 Transplant outdoors: May 3 – May 10 |
| Peppers | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: May 10 – May 17 |
| Eggplant | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: May 10 – May 17 |
| Broccoli | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: Mar 29 – Apr 12 |
| Cabbage | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: Mar 29 – Apr 12 |
| Onions (sets) | Plant outdoors: Mar 29 – Apr 12 |
| Peas | Sow outdoors: Mar 15 – Mar 29 |
| Spinach | Sow outdoors: Mar 15 – Mar 29 |
| Lettuce | Sow outdoors: Mar 29 – Apr 12 |
| Carrots | Sow outdoors: Mar 29 – Apr 12 |
| Potatoes | Plant outdoors: Mar 29 – Apr 12 |
| Beans | Sow outdoors: May 3 – May 10 |
| Sweet corn | Sow outdoors: May 3 – May 10 |
| Cucumbers | Sow outdoors: May 3 – May 10 |
| Squash & zucchini | Sow outdoors: May 3 – May 10 |
| Basil | Start seeds indoors: Mar 15 – Mar 29 Transplant outdoors: May 3 – May 10 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 21 (8 weeks before the average first fall frost on Oct 16).
Useful for zone 6b 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
- Cold frame / mini greenhouse — adds weeks to a short season
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 11 | Apr 26 | May 9 |
| First 32°F frost in fall is before | Nov 1 | Oct 16 | Oct 4 |
How to read it: in spring there is a 10% chance of a frost after May 9, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 4. A hard freeze (28°F) usually ends around April 10.
Hardiness zone by ZIP code in Waterbury
- 06701 zone 6b
- 06702 zone 6b
- 06703 zone 6b
- 06704 zone 6b
- 06705 zone 6b
- 06706 zone 6b
- 06708 zone 6b
- 06710 zone 6b
- 06720 zone 6b
- 06721 zone 6b
- 06722 zone 6b
- 06723 zone 6b
- 06724 zone 6b
- 06725 zone 6b
- 06726 zone 6b
- 06749 zone 6b
Nearby cities
Questions
What growing zone is Waterbury, CT?
Waterbury 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 Waterbury?
The average last spring frost (32°F) in Waterbury is April 26. There is still a 10% chance of frost until May 9.
When can I plant tomatoes in Waterbury?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 3 – May 10. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Meriden Markham Muni Ap, CT (USW00054788), 19.4 km (12.0 mi) from the city center, elevation 31 m, based on 19 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.