Oshkosh, Wisconsin planting calendar and frost dates
Oshkosh is in USDA hardiness zone 5b. The last spring frost typically comes around April 24 and the first fall frost around October 20, giving about 178 frost-free days a year.
- Hardiness zone
- Zone 5b
- Typical last frost
- April 24
- Typical first frost
- October 20
- Frost-free season
- 178 days
Frost dates in Oshkosh
Last spring frost
- April 10Risky: frost later than this in 9 years out of 10
- April 24Typical: a later frost in half of years
- May 8Safe: a later frost only 1 year in 10
First fall frost
- October 4Risky: frost earlier than this 1 year in 10
- October 20Typical: an earlier frost in half of years
- November 2Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 178 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 13 and returns around October 31.
NOAA U.S. Climate Normals 1991-2020 for Oshkosh, 3.1 miles SSW of the city center. 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 Oshkosh
January
Start indoors: collard greens, leeks, onions, petunias, ranunculus
February
Start indoors: black-eyed susans, broccoli, cabbages, cauliflower, chives, collard greens, kale, leeks, lettuce, marigolds, onions, oregano, parsley, petunias, ranunculus, rosemary, sage, snapdragons
March
Start indoors: black-eyed susans, cabbages, cauliflower, celery, chives, cilantro, collard greens, eggplants, ginger, lettuce, marigolds, nasturtiums, peppers, ranunculus, sage, snapdragons, spinach, swiss chard, tomatoes
Plant or sow outdoors: beets, black-eyed susans, blackberries, blueberries, broccoli, cauliflower, chives, cilantro, collard greens, figs, garlic, gladioli, grapes, grass seed, hollyhocks, kale, leeks, onions, peas, poppies, radishes, ranunculus, raspberries, rhubarb, roses, spinach, strawberries, swiss chard, turnips, wildflowers
April
Start indoors: basil, cantaloupes, cosmos, cucumbers, eggplants, okra, peppers, pumpkins, ranunculus, tomatoes, watermelons, winter squash, zucchini
Plant or sow outdoors: asparagus, beets, black-eyed susans, blackberries, broccoli, cabbages, carrots, cauliflower, chives, cilantro, collard greens, dahlias, dill, figs, garden mums, gladioli, grapes, green onions, lavenders, leeks, lettuce, lilies, marigolds, mints, nasturtiums, onions, oregano, parsley, petunias, potatoes, radishes, ranunculus, rosemary, roses, sage, snapdragons, spinach, sunflowers, sweet corn, swiss chard, thyme, turnips
May
Start indoors: cantaloupes, cosmos, cucumbers, okra, pumpkins, watermelons, winter squash, zinnias, zucchini
Plant or sow outdoors: asparagus, basil, cantaloupes, chives, cilantro, cucumbers, dahlias, dill, eggplants, garden mums, ginger, gladioli, grapes, green beans, green onions, kentucky bluegrass, lavenders, lettuce, lilies, marigolds, mints, nasturtiums, oregano, parsley, peppers, perennial ryegrass, petunias, potatoes, pumpkins, ranunculus, rosemary, sage, spinach, st. augustinegrass, 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, 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, beets, broccoli, cabbages, cauliflower, clematis, coneflowers, crocuses, daffodils, daylilies, grass seed, hostas, hyacinths, hydrangeas, kale, lilies, ornamental alliums, peonies, radishes, roses, saffron, spinach, tulips, turnips
October
Plant for fall: crocuses, daffodils, garlic, hyacinths, lilies, ornamental alliums, peonies, tulips
November
Plant for fall: crocuses, garlic, hyacinths, ornamental alliums, tulips
Frost dates and zones by ZIP code in Oshkosh
Oshkosh's 3 main ZIP codes take their frost dates from 2 different NOAA stations: the typical last frost ranges from April 24 in 54901 to April 30 in 54904. Every one of them is in zone 5b.
Planting dates for popular crops in Oshkosh
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Mar 27 to Apr 10 | May 22 to Jun 5 | — |
| Strawberries | — | Mar 13 to 27 | — |
| Lettuce | Feb 27 to Mar 13 | Apr 17 to May 1 | Jul 21 to Aug 25 |
| Cilantro | Mar 13 to 27 | Apr 24 to May 1 | — |
| Basil | Apr 3 to 17 | May 22 to 29 | — |
| Potatoes | — | Apr 28 to May 5 | — |
| Garlic | — | Mar 13 to 27 | Oct 20 to Nov 3 |
| Onions | Jan 2 to Feb 13 | Mar 27 to Apr 10 | — |
| Cucumbers | Apr 24 to May 8 | May 22 to Jun 5 | — |
| Pumpkins | Apr 24 to May 8 | May 22 to Jun 5 | — |
| Peppers | Mar 6 to Apr 3 | May 22 to Jun 5 | — |
| Carrots | — | Apr 3 to 24 | Jul 28 to Aug 18 |
| Sweet Potatoes | — | Jun 5 to 12 | — |
| Watermelons | Apr 17 to May 1 | May 22 to Jun 5 | — |
| Sweet Corn | — | Apr 28 to May 12 | — |
| Green Beans | — | May 22 to Jun 5 | — |
| Zucchini | Apr 24 to May 8 | May 22 to Jun 5 | — |
| Broccoli | Feb 6 to 27 | Mar 27 to Apr 10 | Aug 4 to Sep 1 |
| Peas | — | Mar 13 to 27 | Jul 28 to Aug 11 |
| Spinach | Mar 13 to 20 | Apr 17 to May 1 | Aug 11 to Sep 15 |
| Sunflowers | — | Apr 28 to May 19 | — |
| Zinnias | May 26 to Jun 2 | Jun 23 to Jul 7 | — |
| Tulips | — | — | Sep 8 to Nov 3 |
| Daffodils | — | — | Sep 8 to Oct 20 |
| Grass Seed | — | Mar 13 to 27 | Sep 8 to 22 |
Nearby cities
- Appleton, WI zone 5b, last frost May 4
- Green Bay, WI zone 5b, last frost Apr 30
- Waukesha, WI zone 5b, last frost May 1
- Milwaukee, WI zone 5b, last frost Apr 19
- West Allis, WI zone 5b, last frost Apr 19
- Madison, WI zone 5b, last frost May 1
Planting in WisconsinAbout zone 5bPrintable calendar for Oshkosh
Questions
When is the last frost in Oshkosh?
Around April 24 in a typical year, based on NOAA's 1991-2020 records for Oshkosh. There is still a 1 in 10 chance of frost after May 8.
What planting zone is Oshkosh in?
USDA hardiness zone 5b (2023 map). The zone tells you which perennials survive the winter; planting dates depend on frost dates instead.
When should I plant tomatoes in Oshkosh?
Start seeds indoors March 27 to April 10 and set plants out May 22 to June 5.
When is the first frost in Oshkosh?
Around October 20 in a typical year, and before October 4 about 1 year in 10.