Grow Lesser-Known Nightshade Plants: Ground Cherry, Cape Gooseberry, Tomatillo and More
The paradoxical attributes of the Nightshade family (Solanaceae) are well known to most vegetable gardeners. Typically we eat them for their edible fruits, raw and cooked, with one notable exception, the potato, which is eaten for its tubers. The poisonous properties of these plants are well known; or at least we know them sufficiently well to never dream of eating tomato or pepper foliage, and hopefully use extreme caution when encountering an unknown fruit from this family.
But a number of minor Solanaceous plants are well worth growing for their fruits.
There are many species of husk tomato, genus Physalis, mostly native to the Americas, not cultivated and tending to be weeds with undistinguished edible fruits. A few, such as ground cherries and tomatillos, are cultivated, and many selections have been made. What makes Physalis unique is that the fruit is enclosed by its inflated calyx, a husk, and hence the group name “husk tomatoes.”
At the top of my list is the ground cherry, Physalis pruinosa. Native to North America, this plant has become better known in the last 15 years, but it has been cultivated since Colonial times, harvested by the Pennsylvania Dutch in the 18th century, among others. Native Americans in both North and South America used various Physalis for food and medicine. Philip Miller’s Gardener’s Dictionary mentions a number of types he had been cultivating since 1725 in England.
The epithet “ground cherries” is used generally to describe many types of Physalis, but these plants are 1 to 2 feet tall but low-sprawling, yielding lots of marble-sized orangish-yellow fruits enclosed in a papery husk. Whether this plant got its name because the plant sprawls close to the ground or most of the ripe fruit end up on the ground is not clear.
Plants can be started indoors in early spring, March to April depending upon where you live, and start yielding around 60 to 70 days after transplant. Self-sown plants, of these and other husk tomatoes, are common and can become weedy. The plants grow relatively fast. Self-sown plants will set some ripe fruit in all but the coldest growing regions. Commercial production is limited because fruits have to be hand picked and the husks removed before eating. They have a unique flavor with a hint of tropical fruit, sweet combined with a bit of tart. They make great fresh eating, are useful for jams and pies, and dry easily for a raisinlike snack.
Plants don’t respond well to training on stakes, cages, or trellising because of their sprawling habit, but you can try to keep some of the branches off the ground through any of these methods. Once the fruit begins ripening, you have to pick it fairly regularly or you’ll be picking fruit off the ground. Plastic mulch helps keep the fruit clean and makes harvesting easier. It is best to avoid eating green fruits from this group, as some species may contain solanine, a poisonous principle. The husk allows the fruit to remain clean on the ground and prevents the fruit from becoming rotten as quickly as tomatoes.
Many catalogs carry seed. There are several named varieties, and all have subtle but distinct taste differences. Aunt Molly’s is one variety originally from Poland rescued from the brink of extinction. Cossack Pineapple is another, named for its vaguely pineapplelike taste.
Cape gooseberry, or poha (Physalis peruviana), either originated in the highlands of Peru or lowland Brazil. Its name is derived from the Cape of Good Hope, where it was cultivated in the early 19th century. The orange ripe fruit is similar in size to the ground cherry, and the plants are stronger and more upright. The fruit has a distinct sweet tropical taste. I have grown a variety from India that smelled of coconut and orange zest. It does best in a long, hot growing season and is a short-lived perennial in those zones where the temperature does not get much below freezing. Treated as an annual in temperate regions, it is easy to grow plants from seed. Sometimes yields are fairly low in the North. High tunnels or a greenhouse improve the chances of success. It is widely grown commercially in Zimbabwe and Columbia, in addition to other warm countries. The fruit has high levels of vitamins A, C and B-complex, plus anti-cancer, anti-inflammatory, and antioxidant properties.
Tomatillos, Physalis ixocarpa (or P. philadelphica), is the other major cultivated husk tomato. The Latin name refers to the sticky quality of the fruit. Tomatillos have been cultivated in Mexico and Central America for at least a thousand years and are most commonly cooked to make salsa verde. Fruit size is variable, depending on variety, ranging from 3/4 to 2 inches in diameter, and ripe fruit is yellowish-green to yellow to partly or wholly purple, sometimes the fruit bursting out of its husk. Plants are about 2 to 3 feet or taller and can be staked, or more realistically trellised. Plants tend to need a full season to fully ripen fruit, often about 90 days from transplanting.
Typically the fruit is cooked and unripe green fruit can be used. Ripe fruit can be eaten raw, but I don’t like the irritating qualities on my throat. It is easy to cultivate, and as with other husk tomatoes, self-sown plants are plentiful and will produce harvestable fruit. Some long-season varieties may barely set fruit in the North. In Mexico, small fruited types both growing wild in uncultivated fields and cultivated are popular. It is grown most extensively in the United States in the southwest and for specialty Latino markets, and lately they have become much more widely grown.
De Milpa or Purple de Milpa tomatillos have a distinctly stronger flavor with smaller 3/4-inch green to purplish fruits, typical of the type growing wild in Mexican cornfields. Purple Tomatillo produces tall, later-yielding plants with large 1-1/2-inch, partly to mostly purple, sweet fruit, while Tomate Verde fruits ripen yellow-green. Dr. Wyche’s Yellow yields pale yellow 1- to 2-inch fruits with a purple blush. Many other named varieties can be found in seed catalogs.
Wonderberries and relatives
Another interesting but minor garden fruit is wonderberry. Originally developed by noted plant breeder Luther Burbank from a cross between two distinct species, the wonderberry quickly stoked controversy after its initial release in 1909 from many experts and gardeners who felt it was none other than a widespread weed from Europe, Solanum nigrum, black nightshade, which yields small, glossy black berries. Black nightshade is a complex group of species found throughout much of the globe, with many similar and easily misidentified members.
Burbank did not take the most scientific approach to his breeding efforts, and in this case had not created a new variety but instead propagated a previously cultivated but largely unknown plant from Africa called “gsoba,” which has only been recently identified as Solanum retroflexum. Wonderberries are deep blue-black with a faint bloom, about 1/4-inch-plus in diameter, but bigger than the black nightshade. They are quite easy to grow from seed and will mature almost everywhere. The taste is quite pleasant and fruity, and is probably best made into jams, sauces, and pies. Gsoba is commercially produced in South Africa and made into preserves.
While many people think black nightshade and its American counterpart, Solanum americanum berries are poisonous, depending on genetic strain and location conditions, this and some other species in this group can be edible — be careful and do your research! The berries have a pleasant though somewhat insipid taste, and while I have never cooked them, I suspect, like wonderberry, they can make good jams and sauces. Most amazing about this group is that the cooked young leaves of several species are routinely eaten in various parts of the world as a green vegetable with no ill effects. Much more research needs to be conducted on the edibility of this group, so please don’t eat the leaves without more specific information.
Another member of this group is the garden huckleberry, Solanum melanocersasum or S. scabrum, a cultivar from Africa whose 3/4-inch fruit, in addition to the leaves, are consumed. Berries have a pleasant musky taste with a distinct bitterness.
A true Solanaceous oddity is the Litchi Tomato (Solanum sisymbriifolium), which is a spectacularly armed thorny plant, which would ward off most predators, including humans. It produces showy white to purple flowers and rounded 3/4-inch beautiful bright orange-red fruit full of seeds. Native to Brazil, it may be found growing in parts of the eastern U.S. It’s more of a conversation piece than anything else.
There are a variety of other plants from the tomato family that produces edible fruit. Most of these are long-season plants native to, and best grown in, tropical areas. This includes the tree tomato, naranjilla or lulo, pepino, and goji or wolfberry. Try some of these easy-to-cultivate fruits, especially the ground cherry; there is no other fruit that tastes so good and bears all in one season.
Create an edible landscape in your yard with easy-to-grow fruits.
Ethnobotanist and former director of the Eastern Native Seed Conservancy, Lawrence Davis-Hollander enjoys gardening and cooking, as well as admiring bald eagles and seasonal wildflowers at a nearby preserve.
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