If you’ve ever enjoyed a salsa verde sauce, chances are you’ve eaten a tomatillo. These fruits have long shelf-lives and are used extensively in cooking, particularly in Mexican and Central American green sauces. The fruit grows within a husk, which is removed before consumption (all parts of the plant are poisonous except the fruit). In addition to its use in sauces, tomatillo can be used as a tomato substitute or dried and carried as a snack.
I. Appearance and Characteristics
The tomatillo (Physalis philadelphica and Physalis ixocarpa), also known as the Mexican husk tomato,Tomatillo, is a plant of the nightshade family bearing small, spherical, and green or green-purple fruit of the same name.
The tomatillo (from Nahuatl, tomatl) is also known as husk tomato, Mexican ground cherry, large-flowered tomatillo, or Mexican husk tomato. Some of these names, however, can also refer to other species in the genus Physalis. Other names are Mexican green tomato and miltomate.
In Spanish, it is called tomate de cáscara (husk tomato), tomate de fresadilla (little strawberry tomato), tomate milpero (field tomato), tomate verde (green tomato), tomatillo (Mexico; this term means “little tomato” elsewhere), miltomate (Mexico, Guatemala), farolito (little lantern), or simply tomate (in which case the tomato is called jitomate from Nahuatl xitomatl).
The tomatillo genus name Physalis is from New Latin physalis, coined by Linnaeus from Ancient Greek φυσαλλίς (physallís, “bladder, wind instrument”), itself from φυσιόω (physióō, “to puff up, blow up”), φυσώ (physṓ).
Ixocarpa means “slimey fruit”, referencing a sticky or slimey coat often on a Tomatillo before it ruptures from the calyx.
P. ixocarpa is often confused with P. philadelphica due to morphological similarities and the fact that neither species have had a clear type designation. Physalis ixocarpa and Physalis philadelphica have blue anthers that twist after opening, a yellow corolla with five blue-tinged spots or smudges, and a 10-ribbed calyx filled or burst by the berry. The two species differ in flower size and stigma type.
P. philadelphica grow up to 15 to 60 cm (5.9 to 23.6 in) and have few hairs on the stem. The leaves have acute and irregularly separated dents on the side. They are typically about one meter (3.3 ft) in height, and can be either compact and upright or prostrate with a wider, less dense canopy. The leaves are typically serrated and can be either smooth or pubescent.
Flower
Flowers come in several colors: white, light green, bright yellow, and sometimes purple. Flowers may or may not have purple spots toward the center of the corolla. The anthers are typically dark purple to pale blue. Tomatillo plants are highly self-incompatible, and two or more plants are needed for proper pollination. Thus, isolated tomatillo plants rarely set fruit.
Fruit
The tomatillo fruit is surrounded by an inedible, paper-like husk formed from the calyx. As the fruit matures, it fills the husk and can split it open by harvest time. The husk turns brown, and the fruit can be ripe in several colors, including yellow, green, or even purple. The freshness and greenness of the husk are quality criteria.
II. How to Grow and Care
Sunlight
Tomatillos need full sun, so plant them in a south or west-facing area for maximum sunlight daily. Choose an area that receives at least six hours of direct sunlight each day.
Temperature and Humidity
Tomatillos do best when temperatures are around 70°F or higher during the day, and don’t drop below 55°F at night. To ensure success, plant your seeds or transplant seedlings after the last frost. Tomatillos are drought-tolerant and enjoy heat but grow better with a steady supply of moisture.
Watering
Tomatillos are far more drought tolerant than their tomato cousins. These semi-wild plants are willing to withstand similar conditions to their desert-like native lands of Mexico and Meso-America. However, the best yields come from moderately consistent moisture throughout the season, especially during flowering and fruiting.
Inconsistent water (periods of drought and then sudden, deep waterings) can lead to blossom end rot. Aim to give them about an inch of water per week to keep the soil moist, but never soggy.
Soil
Being somewhat wild, tomatillos are not that picky about their soil either. The only thing they really hate is heavy, soggy, clay soils that don’t drain.
If you’re growing in clay soils, consider using raised beds, a broadfork, and ample compost to improve the drainage of the area. However, it’s best to avoid super manure-rich compost that is high in nitrogen. Instead, opt for decayed leaf litter or rotted vegetable compost.
Though their fruits are known for their acidity, tomatillos prefer a soil that is fairly neutral, ideally between 6.5 and 7.0. But remember they aren’t super picky. They will grow just fine as long as there’s sunshine, heat, and regular watering.
Fertilizing
Fertilize the seedlings before planting them in the garden with a liquid fertilizer at half strength, following the product directions. After they are transplanted, sprinkle one tablespoon of 21-0-0 fertilizer near each plant monthly. Don’t overfertilize tomatillos because this delays fruit production and causes leaves to overgrow.
Planting Instructions
Plant perennial tomatillos in an area that receives lots of sunshine. You can plant them directly in the soil, raised beds, or a big container. These fast-growing plants like well-draining soil with plenty of compost mixed in.
Sow tomatillo seeds indoors six to eight weeks before planting time. Transplant seedlings outdoors after soil temperatures are around 60°F. Tomatillos take about three months to grow, so plan accordingly. Plant at least two tomatillo plants near each other to ensure pollination. These plants need ample room and grow; plan for the mature plant to reach about 3-4 feet tall and wide.
Pruning
Pruning tomatillos isn’t necessary. You’ll likely need to stake tomatillo plants like you do tomato plants.
Propagation
Tomatillos are hardy and resilient plants. Powdery mildew, a fungal disease, can spread and cover the foliage, and overwatering can lead to root rot. Aphids and flea beetles are also common pests for tomatillo plants. Flea beetles munch on the leaves, leaving tiny holes. Aphids leave secretions, so check leaves for wet, shiny, or sticky residue.
Pests and Diseases
Thanks to their previously wild nature in the mountains of Mexico and Guatemala, these resilient Solanaceous plants hold their own in the garden. Tomatillos are far more disease-resistant than peppers and tomatoes. Their abundance of sticky fruits are also less likely to get attacked by pests. If you do have any tomatillo problems, they’re usually quick and easy to deal with.
- Potato Beetles
Potato beetles don’t just attack potatoes- they’ll go for tomatillos and tomatoes too. When they target our husked salsa verde plants, they can cause some pretty annoying side effects. The three-striped potato beetles look a lot like cucumber beetles, except they lay orange eggs on the undersides of tomatillo plants and eat the heck out of their leaves.
To prevent potato beetles on tomatillos, use insect netting or row covers early in the season. You can also hand-pick individual beetles. Worst case scenario, use a diluted neem solution spray to kill off potato beetles and repel future colonizers. Diatomaceous earth dusted on the leaves can also be effective at dehydrating the potato beetles and killing them off, however you will need to re-apply if it rains.
- Aphids
These tiny sap-suckers seem to feed on just about every plant in the garden. If you notice them on your tomatillo stems, leaves, or fruits, it’s time to grab a hose and spray down the plants with a strong jet of water to wash the bugs away. You can also apply a diluted pyrethrum or neem oil solution mixed with a dollop of dish soap to smother aphids and kill them off.
- Hornworms
Thankfully, hornworms are pretty uncommon on tomatillo plants. But if they take hold, these caterpillars of the hawkmoth can completely defoliate the tomatillos in just a few days! Although hornworms typically go for other nightshades (namely tobacco and tomatoes), keep an eye out for their fat, green bodies and pick them off before they eat through your salsa verde plants.
- Blossom End Rot
Blossom end rot happens when the flower-end of a tomatillo fruit ends up blackened and rotten inside the husk. The sunken, dark-colored cankers appear on the lower end of tomatillo fruits and usually render them inedible. This isn’t actually caused by a disease, but rather from plant stress. A deficiency in calcium and uneven soil moisture are the main culprits of blossom end rot.
To prevent it, be sure that your tomatillos’ soil is consistently moist throughout the growing season. Amend with crushed eggshells and balanced organic fertilizers and microbiologically-rich compost. Avoid synthetic ammonia-based nitrogen fertilizers that can cause a calcium “lockup” in the soil.
- Early and Late Blight
Like tomatoes, tomatillo foliage can be subject to this grayish-brown fungal disease that usually starts on the lower leaves of the plant. The blight won’t necessarily harm your tomatillo fruits, but it can slow production and harm your plants.
Prevention is key: plant tomatillos with sufficient spacing and air flow, especially in humid climates. Prune off lower tomatillo leaves to keep the plants off the soil.
Add a layer of organic mulch (like chopped leaves or straw) at the base of plants to keep rainwater from splashing spores up onto the leaves. You should also avoid overhead irrigation that may spread blight around the garden.
III. Uses and Benefits
- Ornamental uses
Tomatillo is a popular plant prized for its green or purplish-green fruit. It is commonly grown for its fruit used in salsas and other sauces. It is an essential plant in vegetable gardens. Plant it with peppers, tomatoes, squashes, basil, mint, and other herbs.
- Culinary uses
Tomatillos can be harvested at different stages of ripeness. For salsa verde, harvesting may be done early when the fruit is sour with a light flavor. Tomatillos can be picked later when the fruits are seedier for a sweeter taste. Tomatillos have diverse uses in stews, soups, salads, curries, stirfries, baking, cooking with meats, marmalade, and desserts.
Tomatillos are a key ingredient in fresh and cooked Mexican and Central-American green sauces. The green color and tart flavor are the main culinary contributions of the fruit. Purple and red-ripening cultivars often have a slight sweetness, unlike the green- and yellow-ripening cultivars, so they generally are used in jams and preserves. Like their close relative, the Cape gooseberry, tomatillos have a high pectin content. Another characteristic is that they tend to have a varying degree of a sappy, sticky coating, mostly when used on the green side out of the husk.
Ripe tomatillos are kept refrigerated for about two weeks. They keep longer with the husks removed and the fruit refrigerated in sealed plastic bags. They may also be frozen whole or sliced.
Tomatillos can also be dried to enhance the sweetness of the fruit in a way similar to dried cranberries, with a hint of tomato flavor. The tomatillo flavor is used in fusion cuisines for blending flavors from Latin American dishes with those of Europe and North America.
IV. Harvesting and Storage
Tomatillos are ready for harvest when the fruit fills in the husk. Sometimes, the husk splits as the fruit spills over. Husks also provide a clue; they turn from bright green to a light brownish color when the fruit is ready. When tomatillos begin to ripen, check them a couple of times a week to know when it’s time to harvest. The fruits should feel firm to the touch. Use them within two to three weeks of harvest. The word tomatillo means ‘little tomato,’ which is fitting because they’re often used in similar ways.
