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Tomatillo

Physalis philadelphica · nightshades

At a glance

Light
Full sun
Frost
Tender (estimate)
Start indoors
6 weeks before your last frost
Spacing
90 cm35 in (estimate)
On this page
A tomatillo plant carrying husked fruit
Photo: Frank Vincentz · CC BY-SA 3.0, via Wikimedia Commons.

When do I plant this? › Plan this in your garden ›

The numbers

Sowing depth
0.3–0.6 cm0.1–0.2 in (estimate)
Spacing in row
90 cm35 in (estimate)
Start indoors, weeks before last frost
6
Mature height
0.9–1.5 m3–5 ft (estimate)
Mature spread
90 cm35 in (estimate)
Days to maturity
60–75
Light
Full sun
Feeding
Moderate feeder
Root depth
Medium
Frost tolerance
Tender (estimate)
Lifespan
Annual
Habit
Bush
Value to pollinators
Moderate

USDA PLANTS profile

Numbers we’re less sure of

Many of our estimates come from an extension page we’ve read that gets close without pinning the number down. Others are still our own best guess, and on some the sources disagree. Treat them all as a starting point.

Rules that apply to tomatillo

Don't plant nightshades where nightshades grew in the last 3 years Promising

Don't plant nightshades where nightshades grew in the last 3 years

Promising

If you skip this, you lose real yield. The planner warns you.

How it works: Alternaria solani (early blight) and Septoria lycopersici overwinter on tomato debris and solanaceous weeds; a 2-3 year break plus debris removal starves this inoculum. Fusarium has a very narrow host range, so rotating away from the host is effective. Verticillium is the exception. Its microsclerotia persist ~10 years and it infects 300+ host families, so a garden-scale rotation does not control it.

Evidence: checked against 5 sources in the research-based literature.

The 5 sources

hgic.clemson.edu

Tomato Diseases & Disorders Clemson HGIC
… tomatoes and related vegetables, such as potatoes, peppers, and eggplants, should not be planted on the same land more than once in three years.

content.ces.ncsu.edu

Early Blight of Tomato NC State Extension
Rotate every 2-3 years.

content.ces.ncsu.edu

Septoria Leaf Spot of Tomato NC State Extension
The fungus is known to overwinter on infected tomato debris and solanaceous weed hosts

content.ces.ncsu.edu

Verticillium Wilt of Tomato and Eggplant NC State Extension
The pathogen can survive in the soil without a host for up to 10 years in the form of structures called microsclerotia

umass.edu

Solanaceous, Verticillium Wilt UMass Extension
Verticillium wilt tends to affect a wide range of hosts and can infect many unrelated plants. Fusarium spp., on the other hand, have very narrow host ranges.
Remedy

Plant nightshades in different ground, or wait until 3 years have passed since this ground last held them. Clear and remove the old debris either way, because the inoculum overwinters on it.

Read the full rule › · open in the planner ›

Don't plant anything sensitive to walnut toxin (juglone) within a walnut tree's root zone. Nightshades are sensitive, and so are apple and cabbage. Well established

Don't plant anything sensitive to walnut toxin (juglone) within a walnut tree's root zone. Nightshades are sensitive, and so are apple and cabbage.

Well established

If you skip this, the planting fails. The planner won’t allow it.

How it works: Juglans roots exude hydrojuglone, oxidized to juglone, a respiration inhibitor. The nightshades are highly sensitive; they wilt and die.

Evidence: checked against 2 sources in the research-based literature.

The 2 sources

hort.extension.wisc.edu

Black Walnut Toxicity UW-Madison / Wisconsin Horticulture (Joy, Hudelson & Jull, rev. 2024-02-28)
Vegetables such as tomato, potato, eggplant and pepper ... are particularly sensitive to juglone

yardandgarden.extension.iastate.edu

What plants are sensitive to the juglone produced by black walnuts? Iowa State Univ. Extension & Outreach, Yard and Garden FAQ
… members of the tomato family (tomato, potato, eggplant, pepper).
Remedy

Plant it outside the walnut's root zone, which takes in the whole drip line and beyond. There is no soil treatment for juglone.

Read the full rule › · open in the planner ›

Don't sow or set out tender crops before your last frost date Well established

Don't sow or set out tender crops before your last frost date

Well established

If you skip this, the planting fails. The planner won’t allow it.

How it works: Ice nucleation in leaf tissue.

Evidence: checked against 2 sources in the research-based literature.

The 2 sources

extension.colostate.edu

Vegetable Planting Guide Colorado State Univ. Extension, GardenNotes #720
From seed: around the date of the average last spring frost

extension.umn.edu

Growing tomatillos and ground cherries Univ. of Minnesota Extension
Transplant to the garden after all danger of frost has passed and the soil has warmed.
Remedy

Sow or set out after the last frost date, or start indoors and transplant once it has passed.

Read the full rule › · open in the planner ›

Don't plant a crop that can't mature before your frost-free season ends Well established

Don't plant a crop that can't mature before your frost-free season ends

Well established

If you skip this, the planting fails. The planner won’t allow it.

How it works: The season's accumulated growing degree days (a running total of its warmth) against the total the crop needs to mature, or the crop's days to maturity against the number of frost-free days.

Evidence: checked against 3 sources in the research-based literature.

The 3 sources

montana.edu

Selecting and Growing Cold-hardy Vegetables in Montana MSU Extension, LILA Fall 2023
Once you know the average dates of the last frost in spring and the first frost in fall, count the number of days between. If the “days to maturity” figure for a desired vegetable is a larger number of days and the “frost tolerance” column indicates “none,” the sad truth is that particular vegetable probably won’t grow to maturity.

planttalk.colostate.edu

Growing Warm Season Vegetables Colorado State Univ. Extension, PlantTalk 1809
Check the seed packet for the number of days until maturity so that there will be enough time for plants to grow before the first killing frost.

extension.colostate.edu

Vegetable Gardening in the Mountains Colorado State Univ. Extension
… high elevation areas don’t accumulate enough “growing degree units” (GDUs, also called growing degree days and heat units) to support some of the most coveted warm season vegetables
Remedy

Start it indoors and transplant it, choose a variety with fewer days to maturity, or skip this crop at this site.

Read the full rule › · open in the planner ›

Pests of one plant family spread more easily through a solid block of it A good hunch

Pests of one plant family spread more easily through a solid block of it

A good hunch

If you skip this, it still grows, just less well. The planner suggests it.

How it works: Resource concentration. A specialist locates and holds its host more efficiently at higher host density and continuity, so an unbroken run of one family across adjacent beds is an easier target than the same family separated by a non-host (associational resistance).

Evidence: checked against 2 sources in the research-based literature.

The 2 sources

Organization of a plant-arthropod association in simple and diverse habitats: the fauna of collards (Brassica oleracea) Root 1973
… the resource concentration hypothesis, which states that herbivores are more likely to find and remain on hosts that are growing in dense or nearly pure stands; that the most specialized species frequently attain higher relative densities in simple environments.

Flea beetle movement in a broccoli monoculture and diculture Elmstrom, Andow & Barclay 1988
… strong, direct support for the hypothesis that host plants are harder to find and easier to lose in vegetationally diverse habitats than in monocultures.
Remedy

Where one family fills adjacent beds in a single season, breaking the run with a non-host family between them lengthens the distance the specialist must travel to the next host. The app discloses this and never docks a score. A continuous single-family block can be the right call anyway (a wind-pollinated crop like corn sets better massed), so the app names the trade-off and leaves the choice to the gardener.

Read the full rule › · open in the planner ›

Cold-hardy annuals can be sown or transplanted before the last spring frost (hardy crops about three weeks before, half-hardy about two weeks before). Tender crops wait for the frost itself. Promising

Cold-hardy annuals can be sown or transplanted before the last spring frost (hardy crops about three weeks before, half-hardy about two weeks before). Tender crops wait for the frost itself.

Promising

If you skip this, it still grows, just less well. The planner suggests it.

How it works: Cold hardiness. Hardy crops tolerate hard frost and half-hardy crops tolerate light frost, so they can occupy the ground weeks before frost-tender crops are allowed in. The offset is measured from the last spring frost.

Evidence: checked against 2 sources in the research-based literature.

The 2 sources

extension.illinois.edu

Time Your Vegetable Plantings by Cold Hardiness University of Illinois Extension
… withstand freezing temperatures and hard frosts without injury

extension.colostate.edu

Vegetable Planting Guide Colorado State Univ. Extension, GardenNotes #720
As early as 2-4 weeks before the date of the average last spring frost

Plus 2 working notes on how the sources were read.

Read the full rule › · open in the planner ›

Long-season warm crops are started indoors several weeks before the last frost and set out after it. Tomato and tomatillo go about six weeks ahead, pepper and eggplant about eight, basil six. Promising

Long-season warm crops are started indoors several weeks before the last frost and set out after it. Tomato and tomatillo go about six weeks ahead, pepper and eggplant about eight, basil six.

Promising

If you skip this, it still grows, just less well. The planner suggests it.

How it works: A frost-tender crop with a long days-to-maturity cannot mature if it is only direct-sown after the last frost, because the frost-free window is too short. A head start under cover buys the weeks the season lacks; the seedling is set out only once frost has passed, so the transplant date is still frost-gated.

Evidence: checked against 3 sources in the research-based literature.

The 3 sources

extension.umn.edu

Starting seeds indoors University of Minnesota Extension

We summarise this source in our notes rather than quote a line from it.

extension.illinois.edu

When should I start my seeds? University of Illinois Extension
Early-to-mid-March Vegetables & herbs: artichoke, broccoli, cabbage, cauliflower, eggplant, kale, lettuce, oregano

extension.umd.edu

Starting Vegetable Seeds Indoors University of Maryland Extension
Tomato: 5 to 6 weeks

Read the full rule › · open in the planner ›

Frost can form on a night the forecast low is a few degrees above freezing. Promising

Frost can form on a night the forecast low is a few degrees above freezing.

Promising

If you skip this, the planting fails. The planner warns you.

How it works: On a clear, still night leaves lose heat to the open sky, so a leaf can fall to freezing and ice can form in it while the thermometer, a couple of meters up, still reads a few degrees above.

Evidence: checked against 7 sources in the research-based literature.

The 7 sources

www.weather.gov

Frost and Freeze Information NWS Tallahassee
Issued up to 24 hours when temperature is forecast to be between 32° and 36° on nights with calm winds

www.weather.gov

Freeze Watches and Warnings National Weather Service
… temperatures below 28°F for an extended period of time can kill most types of commercial crops and residential plants.

ipm.ucanr.edu

Freezing and Frost UC Statewide IPM Program
Frost occurs when air is warmer than 32°F but plant tissues drop to 32°F or below because plants radiate (lose) heat into the atmosphere, especially during cool, clear nights.

yardandgarden.extension.iastate.edu

Fall Planting of Vegetables Iowa State University Yard and Garden, Aaron Steil and Kim Hilgers
Tender crops will be damaged or destroyed by a light frost

extension.sdstate.edu

Fall Frost Tolerance of Common Vegetables SDSU Extension, Rhoda Burrows
Crops from more-temperate regions can withstand light freezes (28 to 32 degrees Fahrenheit):

extension.umn.edu

A Minnesota guide to garden timing UMN Extension, Robin Trott
A light frost (32°F) can damage tender plants, while a hard frost (28°F or colder) will kill most warm-season crops.

extension.colostate.edu

Frost Protection and Extending the Growing Season CSU Extension GardenNotes #722, Whiting, O'Meara and Wilson
Radiation frosts occur on calm clear nights that lack cloud cover to hold in heat.
Remedy

The evening before, cover the crops at risk with a sheet or frost cloth, never plastic, reaching the ground and loose at the bottom so the soil's warmth can rise under it, and take it off in the morning. A cover helps least in a long, hard freeze.

Read the full rule › · open in the planner ›

Another 135 rules depend on your own garden, like crop rotation, frost dates, sun, spacing and soil. See them all.

Plant teams that place it

When do I plant tomatillo? ›

What grows well with tomatillo? · Something wrong with your tomatillo?

More ways Milpa can help

When do I plant? · What grows well together? · Plan my garden · What can I plant now? · Something wrong in the garden? · Keep a garden diary · Heard a tip?

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Milpa Gardens. “Tomatillo (Physalis philadelphica).” https://milpa.garden/plants/physalis-philadelphica/

A garden planner built on graded evidence. Every claim states its evidence grade and links its sources on the page. Cite it with the grade, and add the date you read it.

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