Danbury, Connecticut planting calendar and frost dates
Danbury is in USDA hardiness zone 6b. The last spring frost typically comes around May 1 and the first fall frost around October 14, giving about 166 frost-free days a year.
- Hardiness zone
- Zone 6b
- Typical last frost
- May 1
- Typical first frost
- October 14
- Frost-free season
- 166 days
Frost dates in Danbury
Last spring frost
- April 18Risky: frost later than this in 9 years out of 10
- May 1Typical: a later frost in half of years
- May 16Safe: a later frost only 1 year in 10
First fall frost
- October 1Risky: frost earlier than this 1 year in 10
- October 14Typical: an earlier frost in half of years
- October 29Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 166 days. Frost here means a low of 32°F at the weather station. A hard freeze (28°F), which damages most hardy crops too, typically ends around April 18 and returns around October 27.
NOAA U.S. Climate Normals 1991-2020 for Danbury Muni Airport, 3.5 miles S of the city center and 274 feet lower. Low-lying and rural spots often frost later in spring and earlier in fall than airports and city centers.
What to plant each month in Danbury
January
Start indoors: onions
February
Start indoors: broccoli, cabbages, cauliflower, collard greens, kale, leeks, onions, oregano, parsley, petunias, ranunculus, rosemary, snapdragons
March
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, leeks, lettuce, marigolds, nasturtiums, oregano, parsley, peppers, petunias, ranunculus, rosemary, sage, snapdragons, spinach, swiss chard, tomatoes
Plant or sow outdoors: black-eyed susans, blueberries, garlic, grapes, grass seed, hollyhocks, kale, onions, peas, poppies, raspberries, rhubarb, strawberries, turnips, wildflowers
April
Start indoors: basil, cantaloupes, cilantro, cosmos, cucumbers, eggplants, marigolds, nasturtiums, okra, peppers, pumpkins, ranunculus, tomatoes, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, blueberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garlic, gladioli, grapes, grass seed, green onions, hollyhocks, kale, leeks, lettuce, onions, parsley, peas, poppies, potatoes, radishes, ranunculus, raspberries, rhubarb, roses, snapdragons, spinach, strawberries, swiss chard, turnips, wildflowers
May
Start indoors: cantaloupes, cosmos, cucumbers, okra, pumpkins, watermelons, winter squash, zinnias, zucchini
Plant or sow outdoors: asparagus, basil, beets, cantaloupes, carrots, chives, cilantro, cucumbers, dahlias, dill, eggplants, figs, garden mums, ginger, gladioli, grapes, green beans, green onions, kentucky bluegrass, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, oregano, parsley, peppers, perennial ryegrass, petunias, pumpkins, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, sweet peas, swiss chard, tall fescue, thyme, tomatoes, watermelons, winter squash, zucchini
June
Start indoors: zinnias
Plant or sow outdoors: asparagus, bermudagrass, cantaloupes, celery, centipedegrass, cosmos, cucumbers, eggplants, green beans, green onions, okra, peanuts, peppers, pumpkins, st. augustinegrass, sweet potatoes, tomatoes, watermelons, winter squash, zinnias, zoysiagrass, zucchini
July
Plant or sow outdoors: bermudagrass, centipedegrass, green onions, st. augustinegrass, zinnias, zoysiagrass
Plant for fall: bearded irises, broccoli, brussels sprouts, carrots, collard greens, lettuce, peas, snapdragons, swiss chard
August
Plant for fall: azaleas, bearded irises, beets, broccoli, cabbages, carrots, cauliflower, clematis, collard greens, coneflowers, daylilies, hostas, hydrangeas, kale, lettuce, peas, radishes, roses, saffron, snapdragons, spinach, swiss chard, turnips
September
Plant for fall: azaleas, bearded irises, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, hydrangeas, kale, lilies, ornamental alliums, peonies, radishes, roses, saffron, spinach, tulips
October
Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
Frost dates and zones by ZIP code in Danbury
All 2 of Danbury's main ZIP codes take their frost dates from Danbury Muni Airport, so the dates on this page apply across the city. Every one of them is in zone 6b.
Planting dates for popular crops in Danbury
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 29 to Apr 12 | May 24 to Jun 7 | — |
| Strawberries | — | Mar 20 to Apr 3 | — |
| Lettuce | Mar 6 to 20 | Apr 24 to May 8 | Jul 15 to Aug 19 |
| Cilantro | Mar 20 to Apr 3 | May 1 to 8 | — |
| Basil | Apr 5 to 19 | May 24 to 31 | — |
| Potatoes | — | Apr 22 to 29 | — |
| Garlic | — | Mar 20 to Apr 3 | Oct 14 to 28 |
| Onions | Jan 9 to Feb 20 | Apr 3 to 17 | — |
| Cucumbers | Apr 26 to May 10 | May 24 to Jun 7 | — |
| Pumpkins | Apr 26 to May 10 | May 24 to Jun 7 | — |
| Peppers | Mar 8 to Apr 5 | May 24 to Jun 7 | — |
| Carrots | — | Apr 10 to May 1 | Jul 22 to Aug 12 |
| Sweet Potatoes | — | Jun 9 to 16 | — |
| Watermelons | Apr 19 to May 3 | May 24 to Jun 7 | — |
| Sweet Corn | — | May 1 to 15 | — |
| Green Beans | — | May 24 to Jun 7 | — |
| Zucchini | Apr 26 to May 10 | May 24 to Jun 7 | — |
| Broccoli | Feb 13 to Mar 6 | Apr 3 to 17 | Jul 29 to Aug 26 |
| Peas | — | Mar 20 to Apr 3 | Jul 22 to Aug 5 |
| Spinach | Mar 20 to 27 | Apr 24 to May 8 | Aug 5 to Sep 9 |
| Sunflowers | — | May 1 to 22 | — |
| Zinnias | May 31 to Jun 7 | Jun 28 to Jul 12 | — |
| Tulips | — | — | Sep 2 to Oct 28 |
| Daffodils | — | — | Sep 2 to Oct 14 |
| Grass Seed | — | Mar 20 to Apr 3 | Sep 2 to 16 |
Nearby cities
- Bridgeport, CT zone 7a, last frost Apr 5
- Norwalk, CT zone 7a, last frost Apr 5
- Stamford, CT zone 7a, last frost Apr 12
- Milford city, CT zone 7a, last frost Apr 5
- Waterbury, CT zone 6b, last frost Apr 26
- West Haven, CT zone 7a, last frost Apr 17
Planting in ConnecticutAbout zone 6bPrintable calendar for Danbury
Questions
When is the last frost in Danbury?
Around May 1 in a typical year, based on NOAA's 1991-2020 records for Danbury Muni Airport. There is still a 1 in 10 chance of frost after May 16.
What planting zone is Danbury in?
USDA hardiness zone 6b (2023 map). The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Danbury?
Start seeds indoors March 29 to April 12 and set plants out May 24 to June 7.
When is the first frost in Danbury?
Around October 14 in a typical year, and before October 1 about 1 year in 10.