Wisconsin vegetable planting calendar 2027: frost dates and when to plant
In Wisconsin, the average last spring frost is May 1 in Madison and April 19 in Milwaukee (NOAA 1991-2020 normals). Below are planting dates for Madison and Milwaukee for 27 common vegetables and herbs, worked out the way the Rowtime app does it: NOAA's average frost dates for the nearest weather station, with the planting rules of state extension guides. Dates are for the 2027 season.
Rowtime: Garden Planner works these dates out for your own ZIP code in Wisconsin, shows where each one comes from, and recalculates when a planting slips. Get Rowtime on the App Store.
Dates are estimates. Check your local extension office before you plant, and use your own frost records if you have them. Dates shift by a week or more within a state, so pick the city closest to your conditions.
Madison
When to plant tomatoes in Madison?
In Madison, Wisconsin, the average last spring frost is May 1 and the average first fall frost is October 9 (NOAA 1991-2020 normals, UW ARBORETUM - MADISON station, 5.9 km from ZIP 53703). For tomatoes, start seeds indoors April 5 to June 11 and plant out seedlings May 17 to July 11, following University of Maryland Extension (Home & Garden Information Center) and Purdue University Extension. Dates are for the 2027 season; sources last checked October 24, 2026.
Frost dates for Madison (53703)
- Last spring frost: May 1 on average, May 17 for a 10% risk of a later frost.
- First fall frost: Oct 9 on average, Sep 26 for a 10% risk of an earlier frost.
- USDA hardiness zone 5b (PRISM 2023 listing).
| Crop | When |
|---|---|
| Beet | Sow outdoors: Apr 19 to May 3 Sow outdoors for fall: Aug 1 to Aug 29 |
| Broccoli | Start seeds indoors: Mar 15 to Apr 21 Plant out seedlings: Apr 5 to Apr 19 Plant out seedlings for fall: Aug 1 to Aug 29 |
| Cabbage | Start seeds indoors: Mar 8 to Apr 4 Plant out seedlings: Apr 5 to Apr 19 Plant out seedlings for fall: Aug 1 to Aug 29 |
| Carrot | Sow outdoors: Apr 19 to May 3 |
| Cauliflower | Start seeds indoors: Mar 22 to Apr 21 Plant out seedlings: Apr 19 to May 3 Plant out seedlings for fall: Jun 9 to Jul 9 |
| Cucumber | Sow outdoors: May 31 to Jul 31 |
| Eggplant | Start seeds indoors: Apr 22 to May 21 Plant out seedlings: May 31 to Jul 11 |
| Green onion | Plant onion sets: Apr 5 to Apr 19 Plant out seedlings for fall: Aug 1 to Aug 29 |
| Kale | Sow outdoors: Apr 5 to Apr 19 Sow outdoors for fall: Aug 1 to Aug 29 |
| Lettuce | Sow outdoors: Apr 19 to May 3 Sow outdoors for fall: Aug 1 to Aug 29 |
| Melon and watermelon | Sow outdoors: May 31 to Jul 1 |
| Okra | Plant out seedlings: May 31 to Aug 5 |
| Onion | Plant onion sets: Apr 5 to Apr 19 |
| Pea | Sow outdoors: Apr 5 to Apr 19 |
| Pepper | Start seeds indoors: Apr 5 to May 5 Plant out seedlings: May 31 to Jul 11 |
| Potato | Plant seed potatoes: Apr 5 to Apr 19 |
| Snap bean | Sow outdoors: May 17 to Aug 10 |
| Spinach | Sow outdoors: Apr 5 to Apr 19 Sow outdoors for fall: Aug 1 to Aug 29 |
| Summer squash | Sow outdoors: May 31 to Aug 10 |
| Sweet corn | Sow outdoors: May 17 to Jul 11 |
| Sweet potato | Sprout slips indoors: May 6 to Jun 4 Plant out slips: May 31 to Jun 1 |
| Tomato | Start seeds indoors: Apr 5 to Jun 11 Plant out seedlings: May 17 to Jul 11 |
| Winter squash and pumpkin | Sow outdoors: May 31 to Jul 1 |
| Basil | Plant outdoors: Jun 4 to Sep 3 |
| Cilantro | Sow outdoors: Mar 7 to May 4 Sow outdoors for fall: Aug 17 to Aug 31 |
| Dill | Sow outdoors: Apr 19 to May 4 Sow outdoors for fall: Jul 2 to Aug 16 |
| Parsley | Sow outdoors: Apr 22 to May 21 Plant outdoors for fall: Jul 2 to Aug 31 |
Milwaukee
When to plant tomatoes in Milwaukee?
In Milwaukee, Wisconsin, the average last spring frost is April 19 and the average first fall frost is October 29 (NOAA 1991-2020 normals, MILWAUKEE MITCHELL AP station, 10.6 km from ZIP 53202). For tomatoes, start seeds indoors March 24 to May 30 and plant out seedlings May 2 to July 31, following University of Maryland Extension (Home & Garden Information Center) and Purdue University Extension. Dates are for the 2027 season; sources last checked October 24, 2026.
Frost dates for Milwaukee (53202)
- Last spring frost: Apr 19 on average, May 2 for a 10% risk of a later frost.
- First fall frost: Oct 29 on average, Oct 15 for a 10% risk of an earlier frost.
- USDA hardiness zone 6a (PRISM 2023 listing).
| Crop | When |
|---|---|
| Beet | Sow outdoors: Apr 4 to Apr 18 Sow outdoors for fall: Aug 20 to Sep 17 |
| Broccoli | Start seeds indoors: Mar 3 to Apr 9 Plant out seedlings: Mar 21 to Apr 4 Plant out seedlings for fall: Aug 20 to Sep 17 |
| Cabbage | Start seeds indoors: Feb 24 to Mar 23 Plant out seedlings: Mar 21 to Apr 4 Plant out seedlings for fall: Aug 20 to Sep 17 |
| Carrot | Sow outdoors: Apr 4 to Apr 18 |
| Cauliflower | Start seeds indoors: Mar 10 to Apr 9 Plant out seedlings: Apr 4 to Apr 18 Plant out seedlings for fall: Jun 29 to Jul 29 |
| Cucumber | Sow outdoors: May 16 to Aug 20 |
| Eggplant | Start seeds indoors: Apr 10 to May 9 Plant out seedlings: May 16 to Jul 31 |
| Green onion | Plant onion sets: Mar 21 to Apr 4 Plant out seedlings for fall: Aug 20 to Sep 17 |
| Kale | Sow outdoors: Mar 21 to Apr 4 Sow outdoors for fall: Aug 20 to Sep 17 |
| Lettuce | Sow outdoors: Apr 4 to Apr 18 Sow outdoors for fall: Aug 20 to Sep 17 |
| Melon and watermelon | Sow outdoors: May 16 to Jul 21 |
| Okra | Plant out seedlings: May 16 to Aug 25 |
| Onion | Plant onion sets: Mar 21 to Apr 4 |
| Pea | Sow outdoors: Mar 21 to Apr 4 |
| Pepper | Start seeds indoors: Mar 24 to Apr 23 Plant out seedlings: May 16 to Jul 31 |
| Potato | Plant seed potatoes: Mar 21 to Apr 4 |
| Snap bean | Sow outdoors: May 2 to Aug 30 |
| Spinach | Sow outdoors: Mar 21 to Apr 4 Sow outdoors for fall: Aug 20 to Sep 17 |
| Summer squash | Sow outdoors: May 16 to Aug 30 |
| Sweet corn | Sow outdoors: May 2 to Jul 31 |
| Sweet potato | Sprout slips indoors: Apr 24 to May 23 Plant out slips: May 16 to Jun 21 |
| Tomato | Start seeds indoors: Mar 24 to May 30 Plant out seedlings: May 2 to Jul 31 |
| Winter squash and pumpkin | Sow outdoors: May 16 to Jul 21 |
| Basil | Plant outdoors: May 23 to Aug 22 |
| Cilantro | Sow outdoors: Feb 23 to Apr 22 Sow outdoors for fall: Sep 6 to Sep 20 |
| Dill | Sow outdoors: Apr 7 to Apr 22 Sow outdoors for fall: Jul 22 to Sep 5 |
| Parsley | Sow outdoors: Apr 10 to May 9 Plant outdoors for fall: Jul 22 to Sep 20 |
Sources
Planting rules, in the order Rowtime tries them here:
- Purdue University Extension, Indiana Vegetable Planting Calendar (HO-186-W). Checked October 20, 2026.
- University of Maryland Extension (Home & Garden Information Center), Vegetable Planting Calendar for Central Maryland. Checked October 24, 2026.
- NC State Extension, Central North Carolina Planting Calendar for Annual Vegetables, Fruits, and Herbs (AG-756-01). Checked October 21, 2026.
Frost dates, locations and zones:
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991-2020 annual/seasonal (freeze probabilities).
- U.S. Census Bureau, 2025 Gazetteer Files: ZIP Code Tabulation Areas.
- PRISM Group, Oregon State University / USDA ARS, 2023 USDA Plant Hardiness Zone Map ZIP code listings. PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed 20 Oct 2026.
How the dates are worked out: a guide's rule such as "two weeks after the last frost" is applied to the station's NOAA date. Purdue's dates are 10% dates, so they are counted from the station's 10% date. When a guide gives no last date, the window closes early enough for the crop's longest days to harvest before the first fall frost. When a guide gives no first date for a fall planting, no fall window is shown. "Season too short" means the guide's window would close before it opens at this station's frost dates.
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