Vegetable · Solanaceae
Tomatillo
Physalis philadelphica
Grow a pair under full sun, and thin papery husks swell tight around firm green fruit all season.
Full sun
Every 4–7 days
59–86°F · 15–30°C
60–100 days
Overview
The tomatillo carries each fruit inside a thin, papery husk that wraps it close and dry to the touch. Within sits a firm green berry, the tart core of a salsa verde. It shares the nightshade family with the tomato yet grows as its own plant, Physalis philadelphica, with firmer flesh and a sharper edge. Grown across Mexico and Central America for centuries, its fruit fills out green rather than reddening.
Above the fruit the plant builds fast into a large, sprawling frame of branching green stems clothed in dark-green leaves. As a warm-season annual it spreads wide and low unless a cage or stake lifts it, and the lowest leaves often lie right against the soil. One trait shapes the whole crop: a lone plant fills few husks. Set two or more together so their flowers pollinate, and the husks swell out plump instead of staying flat and empty.
Given full sun and steady water, the plant packs its branches with fruit, each husk tightening around the berry as it grows. The signal to pick is a change in the husk itself: it turns from green to tan and splits open along its seams. The fruit inside stays firm to the squeeze rather than soft, its skin a clean green.
Care
The short version: tomatillos take full sun and rich, well-drained soil, drink about an inch of water a week, and need at least two plants close together so their flowers pollinate and the green fruit fills out.
Light
Tomatillos want full sun and as many hours of direct light a day as they can get. Starved of light, the stems stretch thin and leggy and the plant sets few flowers and little fruit.
Water
Give about 1 inch of water a week and keep the soil evenly moist, which fills the fruit out to an even green. Once rooted in, the plant takes a short dry spell, so soak it deeply once or twice a week rather than in shallow sips. Water at the base and keep the broad leaves dry to hold disease off.
Soil
Root them in rich, well-drained sandy or silty loam dark with organic matter, and keep clear of heavy, wet clay. A pH of 6.0 to 7.0 suits them.
Temperature
They grow best in the warm range of 59°F to 86°F (15°C to 30°C). Frost kills them at either end of the season, so wait to set them out until the cold has fully passed.
Humidity
Everyday outdoor humidity is enough, with no set level to reach. Moving air counts for more, since still, damp foliage packed close together is where disease settles in.
Feeding
Feed lightly at planting in spring and keep nitrogen low, adding phosphorus and potassium only where a soil test points. Too much nitrogen swells the leaves into a deep-green thicket while the flowers and fruit lag behind.
Pruning
Tomatillos take almost no pruning. A stake or cage lifts the sprawling, indeterminate stems off the ground, and stripping the lowest leaves where they touch the soil holds disease down, but heavy cutting is left alone.
Size & spacing
Each plant climbs to 3 to 4 feet (90 to 120 cm) and bushes out about as wide, a dense green mound, so give each one 3 to 4 feet (90 to 120 cm) of ground. That gap lets air slip between the big, branching plants instead of trapping damp among the leaves.
When to plant
Tomatillos want warmth and no frost. The seeds start indoors in late winter, the young dark-green plants move out once the soil warms in late spring, and the husks fill and split from midsummer into fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 6-8 weeks before the last spring frost
- Plant: After all danger of frost has passed and the soil has warmed (late spring)
- Harvest: Harvest about 60-75 days after transplanting, when fruit fills the husk and the husk turns tan and begins to split
Hardiness
USDA hardiness zones: 5–11
Temperature: down to -29°C
Troubleshooting
Most tomatillo trouble is written on the plant in plain sight: flat empty husks, leaves chewed down to a lace of veins, or stems lying across the soil. Caught early, each is easy to reverse. Match the look below and act while it still helps.
Papery husks that stay flat and hollow
The look of empty, papery husks points to a pollination gap, not the soil. A tomatillo needs a partner to fruit, so a lone plant leaves thin husks with little or nothing swelling inside. Grow two close together, cut the nitrogen back, and draw bees in with nearby flowers, and the husks fill with green fruit.
Fix:
- Grow at least two plants, ideally two different varieties, for cross-pollination
- Encourage pollinating insects
- Avoid high-nitrogen fertilizer
Leaves chewed to a lace of veins
The ragged, hole-punched leaves come from several pests, above all the three-lined potato beetle, along with tomato hornworms, cutworms, and flea beetles. Even as the foliage is gnawed, the papery husk keeps each fruit whole underneath. On a small planting, pick the beetles and caterpillars off by hand, crush any egg masses, and keep looking so an early wave never spreads.
Fix:
- Handpick beetles, larvae, and hornworms on small plantings
- Remove and destroy egg masses
- Scout plants regularly
A deep-green plant thick with leaves, thin on fruit
Leaves crowding out fruit trace back to too much nitrogen. The plant stands dark green and dense while flowers and fruit stay scarce. Stop the high-nitrogen feed and give only the phosphorus and potassium a soil test calls for.
Fix:
- Stop applying high-nitrogen fertilizer
- Apply phosphorus and potassium per soil test only as needed
Stems bowed flat across the soil
The tomatillo grows into a large, branching, indeterminate plant, and the weight of the fruit bows its stems to the ground. A cage or stake with the main stems tied up holds the frame upright. Set the support in at transplanting, before the plant is a wide tangle.
Fix:
- Stake or cage plants for support
- Tie up main stems as they grow
Toxicity
The firm ripe fruit, freed from its husk, is good to eat, but the green parts of the plant are not. The dark-green leaves, the stems, and any unripe green fruit hold a natural compound called solanine that upsets the stomach. Keep this green material away from pets, livestock, and small children, and bring only the firm ripe fruit to the kitchen.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Caution
A cat that bites into a leaf or a green, unripe fruit may drool, turn from its food, and feel queasy. Those green parts hold solanine, so the dark foliage stays well out of a cat's reach.
Dogs Caution
A dog that chews the leaves or green fruit can drool, vomit, and slump into a tired heap. The cases run mild, yet the leaves and stems are no browse for a dog.
Horses Caution
The green plant parts can leave a horse slobbering and dull with a sour stomach. Watch grazing horses near any stray plants along a paddock edge.
Rabbits Caution
Solanine laced through the leaves and stems makes the foliage a poor mouthful for rabbits. Leave the greens off the plate rather than risk a digestive upset.
Livestock Caution
Cattle, goats, and sheep can react to the solanine in the foliage and unripe fruit with gut and nervous-system trouble. Fence them clear of the plants and clear away any stems and husks within reach.
Birds Caution
The green parts are best kept from poultry and pet birds, since the same alkaloid reaches them too. A piece of the ripe, husked fruit is a far safer bite for a bird.
People Ripe fruit safe
For people, the firm ripe fruit, husk peeled back, is a kitchen staple and safe to cook and eat. The green leaves, stems, and unripe fruit stay out of the pot, since those hold solanine.
The ripe, husk-filled, firm fruit is safe to eat and is the harvested vegetable. Only the leaves, stems, and unripe (immature) fruit are the concern; keep pets and children from chewing green plant parts and discard unripe fruit and husks.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
The named tomatillos differ most in the size and color of the fruit, from flat green types to large green selections and small purple ones. These are the ones worth knowing on sight.
Toma Verde
Ripens flat, apple-green fruit early, with a bright, tangy bite.
Purple de Milpa
Sets smaller fruit that blush purple over green, carrying a sharper, more intense tartness than the green types.
Grande Rio Verde
A green tomatillo that swells large, sizable fruit in heavy numbers.
Gigante
A vigorous grower whose green fruit reaches a notably big size.
How to propagate
Tomatillos rise easily from seed sown indoors, in the same way as tomatoes, with one rule shaping the tray: more than a single plant goes in.
SeedEasy
Start seeds indoors 6-8 weeks before the last spring frost; transplant after frost danger passes and soil warms · Transplant-ready in roughly 6-8 weeks; fruiting begins about 60-100 days after transplanting
Tomatillos sprout readily from seed sown indoors, just as tomatoes are, about 6 to 8 weeks before your last spring frost. The young plants stand ready to set out within that same span, once the frost has passed and the soil has warmed. Sow two or more plants so their flowers can cross-pollinate, and the first green fruit shows around 60 to 100 days after transplanting.
Myths
Tomatillos are unripe green tomatoes.
The tomatillo is a plant all its own, Physalis philadelphica, and every fruit forms inside a papery husk no tomato grows. It colors up while green and stays firmer to the touch and far tarter than any tomato.
A single tomatillo plant will fruit fully by itself.
A lone plant fills almost no husks, since tomatillos depend on cross-pollination. Grow at least two together, ideally two varieties, and the green fruit follows.
The whole tomatillo plant is edible, like the fruit.
Only the ripe, husked fruit is safe to eat. The green leaves, stems, and unripe fruit carry solanine-type alkaloids and are poisonous, kept out of the kitchen and away from grazing animals.