Waukesha, Wisconsin planting calendar and frost dates
Waukesha is in USDA hardiness zone 5b. The last spring frost typically comes around May 1 and the first fall frost around October 13, giving about 162 frost-free days a year.
- Hardiness zone
- Zone 5b
- Typical last frost
- May 1
- Typical first frost
- October 13
- Frost-free season
- 162 days
Frost dates in Waukesha
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 18Safe: a later frost only 1 year in 10
First fall frost
- September 29Risky: frost earlier than this 1 year in 10
- October 13Typical: an earlier frost in half of years
- October 25Late: frost before this in 9 years out of 10
The growing season between the typical last and first frosts is about 162 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 19 and returns around October 23.
NOAA U.S. Climate Normals 1991-2020 for Waukesha Wwtp, 2.5 miles ESE of the city center and 106 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 Waukesha
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
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, celery, 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, 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, potatoes, 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, basil, 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, okra, 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 Waukesha
All 4 of Waukesha's main ZIP codes take their frost dates from Waukesha Wwtp, so the dates on this page apply across the city. Every one of them is in zone 5b.
Planting dates for popular crops in Waukesha
| Plant | Start indoors | Plant or sow outdoors | Fall planting |
|---|---|---|---|
| Tomatoes | Apr 1 to 15 | May 27 to Jun 10 | — |
| Strawberries | — | Mar 20 to Apr 3 | — |
| Lettuce | Mar 6 to 20 | Apr 24 to May 8 | Jul 14 to Aug 18 |
| Cilantro | Mar 20 to Apr 3 | May 1 to 8 | — |
| Basil | Apr 8 to 22 | May 27 to Jun 3 | — |
| Potatoes | — | Apr 28 to May 5 | — |
| Garlic | — | Mar 20 to Apr 3 | Oct 13 to 27 |
| Onions | Jan 9 to Feb 20 | Apr 3 to 17 | — |
| Cucumbers | Apr 29 to May 13 | May 27 to Jun 10 | — |
| Pumpkins | Apr 29 to May 13 | May 27 to Jun 10 | — |
| Peppers | Mar 11 to Apr 8 | May 27 to Jun 10 | — |
| Carrots | — | Apr 10 to May 1 | Jul 21 to Aug 11 |
| Sweet Potatoes | — | Jun 11 to 18 | — |
| Watermelons | Apr 22 to May 6 | May 27 to Jun 10 | — |
| Sweet Corn | — | May 1 to 15 | — |
| Green Beans | — | May 27 to Jun 10 | — |
| Zucchini | Apr 29 to May 13 | May 27 to Jun 10 | — |
| Broccoli | Feb 13 to Mar 6 | Apr 3 to 17 | Jul 28 to Aug 25 |
| Peas | — | Mar 20 to Apr 3 | Jul 21 to Aug 4 |
| Spinach | Mar 20 to 27 | Apr 24 to May 8 | Aug 4 to Sep 8 |
| Sunflowers | — | May 1 to 22 | — |
| Zinnias | Jun 1 to 8 | Jun 29 to Jul 13 | — |
| Tulips | — | — | Sep 1 to Oct 27 |
| Daffodils | — | — | Sep 1 to Oct 13 |
| Grass Seed | — | Mar 20 to Apr 3 | Sep 1 to 15 |
Nearby cities
- West Allis, WI zone 5b, last frost Apr 19
- Milwaukee, WI zone 5b, last frost Apr 19
- Racine, WI zone 6a, last frost Apr 20
- Kenosha, WI zone 5b, last frost Apr 28
- Janesville, WI zone 5b, last frost Apr 26
- Waukegan, IL zone 6a, last frost Apr 30
Planting in WisconsinAbout zone 5bPrintable calendar for Waukesha
Questions
When is the last frost in Waukesha?
Around May 1 in a typical year, based on NOAA's 1991-2020 records for Waukesha Wwtp. There is still a 1 in 10 chance of frost after May 18.
What planting zone is Waukesha 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 Waukesha?
Start seeds indoors April 1 to 15 and set plants out May 27 to June 10.
When is the first frost in Waukesha?
Around October 13 in a typical year, and before September 29 about 1 year in 10.