When to plant · 38 cities · zones 5b–6a

When to plant tomatillos in Illinois

Start Tomatillo seeds indoors around Mar 6 and transplant around Apr 24 — the Illinois statewide median, counted from a last spring frost of Apr 17 across 1,402 ZIP codes and 192 NOAA stations.

Mar 6Start indoors6 weeks before last frost
Apr 24Plant outApr 14 – May 4 across the state
Apr 17Last spring frostmedian · 1 in 10 years after May 3
Jul 3First harvest70 days from transplant

The rule: Six weeks indoors, transplant after the last frost, and give each plant 30 inches and a large cage.

Illinois tomatillos, by step

Statewide median last frost Apr 17, first fall frost Oct 21, 2027 season. Each cultivar's own indoor lead time and days to maturity, same engine as the Plan Builder.

CultivarStart indoorsPlant outFirst harvestDays
TomatilloToma VerdeMar 6Apr 24Jul 370 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 Illinois's ZIP codes resolve to.

Tomatillos in Illinois, city by city

Tomatillo, scheduled from each city's nearest NOAA station — the same dates as its frost page.

CityLast frostStart indoorsPlant outFirst harvest
Chicagozone 6aApr 10Feb 27Apr 17Jun 26
Aurorazone 5bApr 19Mar 8Apr 26Jul 5
Napervillezone 5bApr 28Mar 17May 5Jul 14
Jolietzone 5bApr 19Mar 8Apr 26Jul 5
Rockfordzone 5bApr 24Mar 13May 1Jul 10
Elginzone 5bApr 26Mar 15May 3Jul 12
Springfieldzone 6aApr 15Mar 4Apr 22Jul 1
Peoriazone 6aApr 16Mar 5Apr 23Jul 2
Champaignzone 6aApr 15Mar 4Apr 22Jul 1
Waukeganzone 6aApr 30Mar 19May 7Jul 16
Cicerozone 6aApr 11Feb 28Apr 18Jun 27
Bloomingtonzone 6aApr 21Mar 10Apr 28Jul 7
Schaumburgzone 5bApr 30Mar 19May 7Jul 16
Evanstonzone 6aApr 26Mar 15May 3Jul 12
Arlington Heightszone 6aApr 19Mar 8Apr 26Jul 5
Bolingbrookzone 6aApr 20Mar 9Apr 27Jul 6
Decaturzone 6aApr 14Mar 3Apr 21Jun 30
Palatinezone 5bApr 25Mar 14May 2Jul 11
Skokiezone 6aApr 26Mar 15May 3Jul 12
Des Plaineszone 6aApr 16Mar 5Apr 23Jul 2
Orland Parkzone 6aApr 20Mar 9Apr 27Jul 6
Oak Lawnzone 6aApr 10Feb 27Apr 17Jun 26
Mount Prospectzone 6aApr 19Mar 8Apr 26Jul 5
Berwynzone 6aApr 11Feb 28Apr 18Jun 27
Tinley Parkzone 6aApr 23Mar 12Apr 30Jul 9
Wheatonzone 5bApr 28Mar 17May 5Jul 14
Normalzone 6aApr 25Mar 14May 2Jul 11
Oak Parkzone 6aApr 11Feb 28Apr 18Jun 27
Hoffman Estateszone 5bApr 30Mar 19May 7Jul 16
Downers Grovezone 6aApr 28Mar 17May 5Jul 14
Plainfieldzone 5bApr 20Mar 9Apr 27Jul 6
Glenviewzone 6aApr 19Mar 8Apr 26Jul 5
Elmhurstzone 6aApr 16Mar 5Apr 23Jul 2
Lombardzone 6aApr 28Mar 17May 5Jul 14
Buffalo Grovezone 6aApr 19Mar 8Apr 26Jul 5
Molinezone 5bApr 24Mar 13May 1Jul 10
Crystal Lakezone 5bMay 1Mar 20May 8Jul 17
Romeovillezone 6aApr 20Mar 9Apr 27Jul 6

What Illinois tomatillos need

SeedsThe cultivar decides the sauce. Everything downstream is damage control.
  • 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.

StartSoil temperature and light intensity, indoors, weeks before your frost date.
  • 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.

GrowRoot volume, nutrition and structure. Where most home crops actually fail.
  • 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.

HarvestTiming, handling, and weighing what you actually got.
  • 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.

CookReduction, texture, and the non-reactive pans that keep tomato tasting like tomato.
  • 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 Illinois: questions

When should I plant tomatillos in Illinois?

Transplant around Apr 24 at the statewide median; across the state that date runs from Apr 14 in the warmest tenth of Illinois's ZIP codes to May 4 in the coldest. To cut the freeze risk to one year in ten, count from May 3 instead of the median last frost. Use the city table for your own town.

When do I start tomatillos seeds indoors in Illinois?

Around Mar 6 for Tomatillo: 6 weeks before the statewide median last frost, on soil held at 75–85 °F.

When is the last frost in Illinois?

The ZIP-weighted median of NOAA 1991–2020 station medians is Apr 17. In the warmest tenth of Illinois's ZIP codes the median last frost falls on or before Apr 7; in the coldest tenth, on or after Apr 27.

When will Illinois tomatillos be ready to harvest?

Tomatillo planted on the statewide date is ready around Jul 3: 70 days from transplant.

More for Illinois

Tomatillos in every state → · Illinois frost dates → · How frost-date math works →