Boston, KY frost dates
Last spring frostApr 18median date
First fall frostOct 25median date
Growing season190 daysfrost-free
Hardiness zone7aZone 7a
How Boston compares
- In 8 years out of 10, the last spring frost in Boston falls between April 1 and May 6, a 35-day window. The first fall frost falls between October 11 and November 5.
- The median last frost is 2 days later than the Kentucky median of Apr 16.
- Its 190-day growing season is longer than 44% of the 785 Kentucky places with a regular frost season (state median 192 days).
- The last frost is typical for zone 7a, where the median is Apr 16.
- The weather station records an average of 92 nights a year at or below 32°F.
- Compared with Louisville, KY, 53 km away, the last frost here is 15 days later than there and the growing season is 24 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 1 |
| 50% (median) | April 18 |
| 10% (safe for tender plants) | May 6 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 11 |
| 50% (median) | October 25 |
| 90% (late) | November 5 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Boston, KY
Boston, KY frost dates — last frost Apr 18, first frost Oct 25, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Jan 24 to Feb 7Transplant outside: Mar 21 to Apr 4
Start indoors: Feb 7 to Feb 21Transplant outside: May 2 to May 16
Start indoors: Feb 7 to Feb 21Transplant outside: May 2 to May 16
Start indoors: Feb 21 to Mar 7Transplant outside: Apr 25 to May 9
Start indoors: Feb 21 to Mar 7Transplant outside: Mar 28 to Apr 11Sow outdoors: Mar 21 to Apr 25Plant for fall: Aug 30 to Sep 27
Start indoors: Feb 21 to Mar 7Transplant outside: Mar 21 to Apr 4Sow outdoors: Mar 21 to Apr 4Plant for fall: Aug 16 to Sep 6
Start indoors: Feb 21 to Mar 7Transplant outside: Apr 4 to Apr 18Plant for fall: Jul 19 to Aug 9
Start indoors: Feb 21 to Mar 7Transplant outside: Mar 28 to Apr 11Plant for fall: Jul 19 to Aug 9
Start indoors: Feb 21 to Mar 7Transplant outside: Apr 4 to Apr 18Plant for fall: Jul 19 to Aug 9
Start indoors: Mar 7 to Mar 21Transplant outside: May 9 to May 23Sow outdoors: May 9 to May 23
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 25 to May 9
Sow outdoors: Mar 7 to Mar 28Plant for fall: Aug 2 to Aug 23
Sow outdoors: Mar 7 to Mar 28Plant for fall: Aug 30 to Sep 20
Sow outdoors: Mar 14 to Apr 25Plant for fall: Sep 13 to Oct 4
Start indoors: Mar 21 to Mar 28Transplant outside: May 2 to May 9Sow outdoors: Apr 25 to May 9Plant for fall: Aug 9 to Aug 23
Start indoors: Mar 21 to Mar 28Sow outdoors: Apr 25 to May 9Plant for fall: Aug 16 to Aug 30
Start indoors: Mar 21 to Mar 28Sow outdoors: Apr 25 to May 9
Start indoors: Mar 21 to Mar 28Transplant outside: May 2 to May 16
Sow outdoors: Mar 28 to Apr 25Plant for fall: Aug 2 to Aug 16
Sow outdoors: Mar 28 to Apr 25Plant for fall: Aug 16 to Aug 30
Sow outdoors: Mar 28 to Apr 18
Sow outdoors: Apr 4 to May 2Plant for fall: Aug 16 to Aug 30
Sow outdoors: Apr 4 to Apr 25Plant for fall: Aug 30 to Sep 20
Sow outdoors: Apr 25 to May 16Plant for fall: Aug 9 to Aug 23
Sow outdoors: Apr 25 to May 9
Transplant outside: May 2 to May 23
Plant for fall: Oct 11 to Nov 15
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Boston, KY
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 24 – Feb 7 | Mar 21 – Apr 4 | — | — |
| Peppers | Feb 7 – Feb 21 | May 2 – May 16 | — | — |
| Eggplant | Feb 7 – Feb 21 | May 2 – May 16 | — | — |
| Tomatoes | Feb 21 – Mar 7 | Apr 25 – May 9 | — | — |
| Lettuce | Feb 21 – Mar 7 | Mar 28 – Apr 11 | Mar 21 – Apr 25 | Aug 30 – Sep 27 |
| Kale | Feb 21 – Mar 7 | Mar 21 – Apr 4 | Mar 21 – Apr 4 | Aug 16 – Sep 6 |
| Broccoli | Feb 21 – Mar 7 | Apr 4 – Apr 18 | — | Jul 19 – Aug 9 |
| Cabbage | Feb 21 – Mar 7 | Mar 28 – Apr 11 | — | Jul 19 – Aug 9 |
| Cauliflower | Feb 21 – Mar 7 | Apr 4 – Apr 18 | — | Jul 19 – Aug 9 |
| Okra | Mar 7 – Mar 21 | May 9 – May 23 | May 9 – May 23 | — |
| Basil | Mar 7 – Mar 21 | Apr 25 – May 9 | — | — |
| Peas | — | — | Mar 7 – Mar 28 | Aug 2 – Aug 23 |
| Spinach | — | — | Mar 7 – Mar 28 | Aug 30 – Sep 20 |
| Radishes | — | — | Mar 14 – Apr 25 | Sep 13 – Oct 4 |
| Cucumbers | Mar 21 – Mar 28 | May 2 – May 9 | Apr 25 – May 9 | Aug 9 – Aug 23 |
| Zucchini & Summer Squash | Mar 21 – Mar 28 | — | Apr 25 – May 9 | Aug 16 – Aug 30 |
| Winter Squash & Pumpkins | Mar 21 – Mar 28 | — | Apr 25 – May 9 | — |
| Melons & Watermelon | Mar 21 – Mar 28 | May 2 – May 16 | — | — |
| Carrots | — | — | Mar 28 – Apr 25 | Aug 2 – Aug 16 |
| Beets | — | — | Mar 28 – Apr 25 | Aug 16 – Aug 30 |
| Potatoes | — | — | Mar 28 – Apr 18 | — |
| Swiss Chard | — | — | Apr 4 – May 2 | Aug 16 – Aug 30 |
| Cilantro | — | — | Apr 4 – Apr 25 | Aug 30 – Sep 20 |
| Green Beans | — | — | Apr 25 – May 16 | Aug 9 – Aug 23 |
| Sweet Corn | — | — | Apr 25 – May 9 | — |
| Sweet Potatoes | — | May 2 – May 23 | — | — |
| Garlic | — | — | — | Oct 11 – Nov 15 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Bernheim Forest, KY weather station, 20 km away (elevation 551 ft (168 m)).
Frost dates near Boston
- New Haven Apr 16 · Oct 25
- Bardstown Apr 13 · Oct 25
- New Hope Apr 16 · Oct 25
- Nazareth Apr 13 · Oct 25
- Lebanon Junction Apr 18 · Oct 25
- Loretto Apr 13 · Oct 25
- Nerinx Apr 13 · Oct 25
- Saint Francis Apr 13 · Oct 25
- Hodgenville Apr 16 · Oct 25
- Clermont Apr 18 · Oct 25
Frequently asked questions
When is the last frost in Boston, KY?
The median last spring frost in Boston, KY is April 18. There is still about a 10% chance of frost after May 6, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Boston, KY?
The median first fall frost is October 25, with about a 10% chance of frost before October 11.
How long is the growing season in Boston, KY?
About 190 days between the median last spring frost and first fall frost.
What planting zone is Boston, KY?
Boston, KY is in USDA hardiness zone 7a.