When to plant · 16 cities · zones 4b–6a
When to plant tomatillos in Wisconsin
Start Tomatillo seeds indoors around Mar 23 and transplant around May 11 — the Wisconsin statewide median, counted from a last spring frost of May 4 across 779 ZIP codes and 202 NOAA stations.
The rule: Six weeks indoors, transplant after the last frost, and give each plant 30 inches and a large cage.
Wisconsin tomatillos, by step
Statewide median last frost May 4, first fall frost Oct 7, 2027 season. Each cultivar's own indoor lead time and days to maturity, same engine as the Plan Builder.
| Cultivar | Start indoors | Plant out | First harvest | Days |
|---|---|---|---|---|
| TomatilloToma Verde | Mar 23 | May 11 | Jul 20 | 70 from transplant |
Tight means first harvest lands within two weeks of the median first fall frost. Statewide dates are the ZIP-weighted median of every NOAA 1991–2020 station Wisconsin's ZIP codes resolve to; 4 of 783 ZIPs have no datable freeze and are left out.
Tomatillos in Wisconsin, city by city
Tomatillo, scheduled from each city's nearest NOAA station — the same dates as its frost page.
| City | Last frost | Start indoors | Plant out | First harvest |
|---|---|---|---|---|
| Milwaukeezone 6a | Apr 26 | Mar 15 | May 3 | Jul 12 |
| Madisonzone 5a | May 1 | Mar 20 | May 8 | Jul 17 |
| Green Bayzone 5b | May 7 | Mar 26 | May 14 | Jul 23 |
| Kenoshazone 5b | Apr 28 | Mar 17 | May 5 | Jul 14 |
| Racinezone 6a | Apr 24 | Mar 13 | May 1 | Jul 10 |
| Appletonzone 5b | May 4 | Mar 23 | May 11 | Jul 20 |
| Eau Clairezone 4b | May 8 | Mar 27 | May 15 | Jul 24 |
| Waukeshazone 5b | Apr 30 | Mar 19 | May 7 | Jul 16 |
| Oshkoshzone 5b | Apr 24 | Mar 13 | May 1 | Jul 10 |
| Janesvillezone 5b | Apr 26 | Mar 15 | May 3 | Jul 12 |
| West Alliszone 5b | Apr 26 | Mar 15 | May 3 | Jul 12 |
| La Crossezone 5a | Apr 23 | Mar 12 | Apr 30 | Jul 9 |
| Sheboyganzone 6a | May 2 | Mar 21 | May 9 | Jul 18 |
| Wauwatosazone 5b | Apr 26 | Mar 15 | May 3 | Jul 12 |
| Fond du Laczone 5b | May 1 | Mar 20 | May 8 | Jul 17 |
| Brookfieldzone 5b | Apr 26 | Mar 15 | May 3 | Jul 12 |
What Wisconsin tomatillos need
Toma Verde Tomatillo SeedMust have
Salsa verde is not a green tomato sauce — it is a tomatillo sauce, and the difference is the tartness and the natural pectin that makes it cling. There is no substitute.
Organic Seed Starter Potting MixMust have
Seed-starting mix is not potting soil with a nicer label — it is finer, lighter, and low in nutrients on purpose, because a seedling's first roots want air and moisture, not fertiliser.
Seedling Heat Mat + Digital ThermostatMust have
Peppers germinate on soil temperature, not air temperature. At 65 °F a habanero takes a month and half of them rot; at 85 °F it is up in eight days. The thermostat is the half that matters.
T8 Full-Spectrum Grow Lights, 1 ft 4-packMust have
A south window in March delivers a fraction of the light a pepper seedling needs, and the plant tells you by stretching. Two inches of LED above the canopy for 16 hours a day fixes it permanently.
5-Gallon Fabric Grow Bags, 5-Pack
Fabric pots air-prune roots and drain faster than a plastic pot can, which is the entire reason container tomatoes fail. Five gallons is the honest minimum for a pepper; a tomato wants ten.
Ocean Forest Potting SoilMust have
Pre-charged with enough nutrition to carry a transplant for its first month without feeding, which is exactly the window when most container plants stall.
Organic Tomato-Tone 3-4-6 with 8% CalciumMust have
The NPK ratio is the point: low nitrogen, higher potassium. Feed a tomato a high-nitrogen lawn fertiliser and you get a magnificent six-foot plant with four tomatoes on it.
58" Square Tomato Cages, 3-PackMust have
The conical wire tomato ring from the hardware store is 33 inches tall and an indeterminate San Marzano will laugh at it in July. Height and square geometry are what actually hold a loaded plant.
Garden Harvest Basket with Tool Caddy
A harvest basket that doubles as a colander means the hose rinse happens in the garden, and the dirt stays outside. On a 20-pound tomato day that is a genuine time saving.
Stainless Steel Food Mill, 3 discsMust have
A blender pulverises tomato skins and seeds into the sauce, which is where bitterness comes from. A mill separates them out — no blanching, no peeling, no ice bath. It removes an entire hour from sauce day.
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Tomatillos in Wisconsin: questions
When should I plant tomatillos in Wisconsin?
Transplant around May 11 at the statewide median; across the state that date runs from May 3 in the warmest tenth of Wisconsin's ZIP codes to May 26 in the coldest. To cut the freeze risk to one year in ten, count from May 20 instead of the median last frost. Use the city table for your own town.
When do I start tomatillos seeds indoors in Wisconsin?
Around Mar 23 for Tomatillo: 6 weeks before the statewide median last frost, on soil held at 75–85 °F.
When is the last frost in Wisconsin?
The ZIP-weighted median of NOAA 1991–2020 station medians is May 4. In the warmest tenth of Wisconsin's ZIP codes the median last frost falls on or before Apr 26; in the coldest tenth, on or after May 19.
When will Wisconsin tomatillos be ready to harvest?
Tomatillo planted on the statewide date is ready around Jul 20: 70 days from transplant.
More for Wisconsin
- When to plant tomatoes
- When to plant peppers
- When to plant basil
- When to plant onions
- When to plant cilantro
- When to plant carrots
- When to plant mustard greens
Tomatillos in every state → · Wisconsin frost dates → · How frost-date math works →