When to plant · 14 cities · zones 5a–5b
When to plant tomatillos in Iowa
Start Tomatillo seeds indoors around Mar 17 and transplant around May 5 — the Iowa statewide median, counted from a last spring frost of Apr 28 across 964 ZIP codes and 160 NOAA stations.
The rule: Six weeks indoors, transplant after the last frost, and give each plant 30 inches and a large cage.
Iowa tomatillos, by step
Statewide median last frost Apr 28, first fall frost Oct 10, 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 17 | May 5 | Jul 14 | 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 Iowa's ZIP codes resolve to.
Tomatillos in Iowa, 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 |
|---|---|---|---|---|
| Des Moineszone 5b | Apr 18 | Mar 7 | Apr 25 | Jul 4 |
| Cedar Rapidszone 5b | Apr 28 | Mar 17 | May 5 | Jul 14 |
| Davenportzone 5b | Apr 23 | Mar 12 | Apr 30 | Jul 9 |
| Sioux Cityzone 5a | Apr 29 | Mar 18 | May 6 | Jul 15 |
| Ankenyzone 5b | Apr 23 | Mar 12 | Apr 30 | Jul 9 |
| Iowa Cityzone 5b | Apr 21 | Mar 10 | Apr 28 | Jul 7 |
| West Des Moineszone 5b | Apr 18 | Mar 7 | Apr 25 | Jul 4 |
| Ameszone 5b | Apr 26 | Mar 15 | May 3 | Jul 12 |
| Waterloozone 5a | Apr 27 | Mar 16 | May 4 | Jul 13 |
| Council Bluffszone 5b | Apr 18 | Mar 7 | Apr 25 | Jul 4 |
| Dubuquezone 5a | Apr 19 | Mar 8 | Apr 26 | Jul 5 |
| Urbandalezone 5b | Apr 18 | Mar 7 | Apr 25 | Jul 4 |
| Marionzone 5a | Apr 28 | Mar 17 | May 5 | Jul 14 |
| Cedar Fallszone 5a | Apr 27 | Mar 16 | May 4 | Jul 13 |
What Iowa 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 Iowa: questions
When should I plant tomatillos in Iowa?
Transplant around May 5 at the statewide median; across the state that date runs from Apr 27 in the warmest tenth of Iowa's ZIP codes to May 10 in the coldest. To cut the freeze risk to one year in ten, count from May 11 instead of the median last frost. Use the city table for your own town.
When do I start tomatillos seeds indoors in Iowa?
Around Mar 17 for Tomatillo: 6 weeks before the statewide median last frost, on soil held at 75–85 °F.
When is the last frost in Iowa?
The ZIP-weighted median of NOAA 1991–2020 station medians is Apr 28. In the warmest tenth of Iowa's ZIP codes the median last frost falls on or before Apr 20; in the coldest tenth, on or after May 3.
When will Iowa tomatillos be ready to harvest?
Tomatillo planted on the statewide date is ready around Jul 14: 70 days from transplant.
More for Iowa
- 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 → · Iowa frost dates → · How frost-date math works →