Almost every kitchen gardener grows potatoes and tomatoes and maybe sweet or hot peppers or aubergines. But I wonder if they have any idea of how poisonous the other bits of these plants are? And also how many other closely related and very poisonous relations these have? Considering so many of the Solanaceae have extremely poisonous members it is surprising any have edible fruits. And even more surprising is the case of the edible roots of potatoes when the potato fruit which so closely resembles a small green tomato is highly poisonous. The spuds which are really swollen stems only remain edible as long as they do not sprout, or see light when they turn green, as they then become as poisonous as ordinary stems and leaves.
Most of the Solanaceae have poisonous foliage and roots as well as poisonous berries. From tobacco plants, either smoking or the ornamental forms, any part of either plant is deadly if consumed, approx. a cigarettes worth could be fatal. The wild Solanaceae weeds Deadly Nightshade, Atropa belladonna, Thorn apple, Datura stramonium, Henbane, Hyoscyamus niger, Mandrake, Mandagora officinarum, Woody and Black nightshades Solanum dulcamara and S. nigrum are all reckoned extremely dangerous in all parts. In the greenhouse the ornamental pot plant Jerusalem Cherry Solanum pseudocapsicum, the Chalice vine or Trumpet flower Solandra guttata, the useful Shoo-fly plant Nicandra physaloides, and all the Angels trumpets, Brugmansias, all are poisonous in all their parts and not just their berries or seeds. With so many poisonous relations it is not only a wonder that we have edible potatoes and tomatoes, but incredible that there are even more edible and tasty relations.
Sweet and Hot peppers are edible Solanaceae but their foliage is not and likewise for the Aubergine, Eggplant, Solanum melongena. Long grown in the East these were originally called Mad apples, indeed tomatoes were called Love apples. Both were considered risky things to eat for years after their introduction originally for ornamental as much as esculental reasons. It is the flowers that give them away as they are the same five pointed star as with potatoes and tomatoes. Aubergines are harder to grow well than either tomatoes or peppers needing a little bit more warmth and brightness to succeed. Their foliage is larger and softer than the others and more prone to aphids and red spider mite attacks. To produce well they need a good long growing season under cover, they are very unreliable out of doors. Aubergines vary tremendously in the size and colour of their fruits and can be heavy cropping in which case they need staking to support the fruits. Be warned as well as poisonous foliage they are also spiny especially just behind the fruits. They are hungry feeders and do better in the border than in pots as long as the soil is warm enough.
Much less well known though often seen in the shops are the Cape Gooseberries, Physalis peruviana. This plant closely resembles the hardy ornamental P. alkekengi the Chinese Lantern plant, with it’s orangey red balloon enclosed fruits. Although the foliage and balloon are poisonous the fruits of P. alkekengi are not poisonous if cooked as they used to be commonly eaten. The Cape Gooseberries, P. peruviana, are not as hardy but grow very similarly with long lax stems dripping with husks. These contain the orange fruits which are delicious and rich in vitamins, said to freshen breath, heal the enamel on your teeth and make a very good jelly. These easier to grow than tomatoes with fewer problems. However there is a difficulty which is that they are slow to come into cropping from seed. Especially outdoors where they usually fail. However if the Cape Gooseberry is grown the first year and over-wintered than it crops much earlier the following years. Growing quite like a pelargonium in many ways these are about as hardy and can be treated much like one either allowing the plant to become leggy and bushy or pruning back hard each spring. This will be necessary because if not confined in a tub and planted in the border under cover it will get quite vigorous. Given some protection it will come back from the roots if the top is lost. Ideally take cuttings in late summer and over-winter these as they will make sturdy plants that crop sooner the following year. If you fail to pick these fruits as they ripen they drop off which is when they are at their best, when being in a paper wrapping they lie unsullied in the dry for you to collect. If left for weeks they slowly dry to wee raisins still in their paper wrapper.
A sister plant is P. pruinosa/pubescens this is the Husk tomato, Cossack Ground Cherry and a host of other names. It is better in several ways- it is hardier and may well crop outdoors in sheltered spots, it is squatter, bushier and more compact, it is an annual and quicker to crop than then Cape Goooseberry. Sadly of course the fruit is smaller and to some not quite as delectable. Grown under cover it is very productive and the fruits are well liked by some as they have a pineapple tang. It is very productive as a plant half the size of a small tomato plant can give a pound or more of these small fruits which keep naturally late into the winter if stored dry and frost free..
Another Physalis, The Tomatillo, Jamberry, Mexican Husk Tomato, P. Ixocarpa is similar in every way but bigger fruited with a purple or yellow green tomato in a husk which becomes stretched around the swollen midriff like an over tight cardigan. These are grown in the same way as greenhouse tomatoes and like the Cape Gooseberry tend to crop rather late in the year so likewise do better from rooted over-wintered plants than from seed. An essential ingredient of some Salsa dishes and of course their jam this is a possible alternative crop to tomatoes without most of the problems- hardly any diseases or pests bother any of the Physalis.
Solanum muricatum, the Alligator Pear or Pear, is similar to a Physalis with a tender short lived perennial lax shrubby form but instead of small husked fruits you get pear sized plum tomato shaped green fruits with purple markings. Sort of halfway to a melon crossed with an aubergine. This is best cooked with other fruits as it is a bit bland. The plant is lax and very prone to red spider mites and aphids. It has potential but needs improving.
Very different is Solanum quitoense, this has small orange fruits with a sharp delicious taste like orange or passion fruit juice. The plant is quick, very decorative with shapely, purpley coloured leaves, unfortunately it is both tender and very prickly, all over, and gets big, very big. Well worth growing for the striking taste though and as a talking point plant not to tangle with.
We are all warned of the nightshades, so I was surprised when in the USA I was offered what looked to me exactly the same as what I know as Black Nightshade, S. nigrum, the plants were similar and the berries identical, and were made into a pie which we ate, and survived. I guess either our Black nightshade is a different apparently identical sub-species with poisonous berries or ours are not poisonous either if cooked- anyone want to try the experiment? It gets even more complicated when I found that the foliage of another apparently identical S. nigrum in the Caribbean was eaten cooked as spinach!!
You certainly would not want to eat the foliage of many of this big family but that of the Tree tomato, Tamarillo, Cyphomandra betacea. This is so smelly I doubt you could stomach it. The tree tomato is a large almost hardy shrub come a small tree resembling a Datura or Brugmansia in many ways except the flowers are really small and followed by drooping stems of reddy purple plum tomato like fruits -which are usefully available in midwinter if the plant is big enough and under cover. Unfortunately the Tree tomato suffers from every pest and disease common under glass so is a miffy subject, and gets a bit big however the usefulness of a winter fruit crop should not be overlooked.
Another even stranger Solanaceae now much in vogue are the magic Goji berries. Supposedly the latest in a recent plethora of miracle foods these have been around for a very long time under other names. Lycium barbarum is also known as the Wolf berry, the Box thorn, or the Duke of Argyll’s tea plant. It was sent to the Duke a mislabeled specimen in place of a tea plant so he grew it for that purpose originally rather than it’s fruits. Fairly hardy this has gone native in seaside parts of the south west of the UK and is found in various places from Eastern Europe through to northern India and Tibet. The berries are freely borne following small violet flowers on the lax often spiny sprawling stems. The berry itself is insipid and orangey red looking a bit like a small chilli pepper. They are not exactly delicious, but if they are that good for you I suppose that’s no problem.