Here we are at the sixth and final installment of the companion planting series and today the topic focuses on the Nightshade Family. The Nightshade family is scientifically known as the Solanaceae family and it’s not a small family as about 2,700 plants are within it. Although the family originated in South America members of this family now inhabit just about every continent on Earth except for Antarctica. This diversification started after the Cretaceous-Paleogene extinction event 66 million years ago and saw the mass extinction of about 75% of all life on our planet. As such Nightshades diversified over time becoming adapted to thriving in an assortment of land types but also taking on a variety of forms ranging from epiphytes to trees. A number of species developed a chemical defense in the form of high concentrations of Alkaloid compounds; examples of this are the Nicotine in Tobacco or the Capsaicin in Peppers. The name Solanaceae has some uncertain origins, it is clear that it comes from the Latin word Solanum, but it may come from the shape of many Nightshade plant’s flowers resembling a sun. Take a close look at an Eggplant or Tomato flower and you can kind of see how perhaps given the Latin word for the sun is Sol and the yellow flowers of a tomato are very star-like in shape. Eggplants have a more noticeable and similar shape but often is white or purple but they are still shaped similar to a simplistically drawn sun. Some sources suggest Solanum came from the Latin verb ‘Solare’ which means “to soothe” and given the medicinal uses of some nightshades this may have merit. Regardless of the origins of the name, it is clear what role the most common nightshades in cultivation play in the garden when it comes to companion planting. Without further delay here is a look at the most commonly found nightshades in the garden trade and how they fit into companion planting.
Angel’s Trumpet (Brugmansia species)
Angel’s Trumpet when in full bloom is quite the sight to behold since the flowers have scent and are large and dramatic in presentation. However unlike its annual cousin Brugmansia prefers partial shade areas and pairs well with Marigolds and Basil.
Bed of Nails (S. quitoense) & Porcupine Tomato (S. pyracanthum)
These strange Nightshade relatives do double duty in the garden. The Bed of Nails has purple spines while the Porcupine Tomato has bright orange-red spines and due to this they both have a role as an annual part of defensive landscaping as most animals and people will not mess with these plants. Only the Bed of Nails bears edible fruit and both can be used to hold soil in place and are considered short-lived perennials if brought in for the winter.
Devil’s Trumpet (Datura metel)
Devil’s Trumpet is sometimes called Jimsonweed, and these days it’s a very cultivated garden annual that comes with double flowers but also has some needs to get the best effect. Datura much like a Tomato needs a lot of organic matter in the soil, regular fertilization and regular irrigation to do its best. Datura pairs well with herbs such as Yarrow, Hyssop, Sage, and flowers such as Marigolds and Verbena.
Eggplant (S. melongena)
Eggplant comes in many shapes, sizes and colors ranging from the traditional Black Beauty to the Turkish Orange Eggplant. According to a few references Eggplant pairs well with Amaranth, and gains protection when planted near beans from Potato Beetles. The one thing most people do not know about eggplant is that they are very drought resistant once established and make excellent candidates for xeric gardening.
Garden Huckleberry & Sunberry (S. melanocerasum) (S. retroflexum)
While the berries themselves are unsafe to eat until fully colored up, this plant adds a critical bit of value to your garden in terms of companion planting. In trials it was found that this plant was the preferred nesting site for Assassin bugs which are insatiable hunters of other insects. If grown in large pots that are moved about the garden as pest problems appear These plants help handle it by being a home to even hungrier insects.
Ground Cherry (Physalis pruinosa)
Ground Cherries are grown a lot like a Tomato but have the physical structure that is similar to Peppers in that they aren’t a vine, and they have this unique ‘V’ stem and branching structure. Ground cherries are easy to grow and you can tell the fruit is ripe when you gently jiggle the plant and the fruits fall off. Companion planting options for Ground Cherries include Basil, Thyme, Carrots, Marigolds and Peppers.
Nightshade Greens (S. macrocarpon) (S. scabrum)
The two species of Nightshade greens are best known for their edible leaf greens. While they both produce fruits the edibility of the fruit is not quite clear. Nightshade greens are a bitter green akin in flavor to something like Broccoli Rabe, and they are a bit rare in the United States. In growing trials last year (S. scabrum) produced four feet tall plants with large leaves that needed no support and seemed to help everything around them grow. The other Nightshade green (S. macrocarpon) which is actually a type of Eggplant, seemed to follow normal growing practices for an domesticated eggplant, but had far better heat and drought tolerance.
Peppers (Capsicum annuum) (C. frutescens) (C. chinense)
While there is no consensus on exactly how many varieties of cultivated peppers there are the range estimates upwards of 50,000 or more cultivated types. In general peppers grow well with a number of leaf greens such as Dandelion, Chicory and Lettuce but Sweet peppers are known to grow well with Basil and Okra.
Petunia (Petunia x atkinsiana)
Petunias are a fairly common annual flower available in a wide range of bloom colors and come in double and triple bloom forms. A smaller flowered cousin the Calibrachoa, a short-lived perennial fills in if you desire smaller more delicate but also more numerous flowers. Petunias in general are known to attract Hummingbirds and also protect Beans against Beetles.
Potato, White (Solanum tuberosum)
Potatoes are something that many gardeners try to grow but find varied degrees of success because they require certain things to be productive. Deep soil that is heavily enhanced with organic matter increases the chances of tubers, but also regular irrigation and fertilizer helps too. The aforementioned practically means that in the home garden growing potatoes in deep containers is the best way to go. In the view of Companion Planting Potatoes do better when planted near Beans, Corn, Cabbages, Marigolds and Eggplants. It is also suggested that planting Flax between rows of Potatoes can help protect against Bean Beetles and Blister beetles.
Tomato (Solanum lycopersicon)
Tomatoes are a garden staple that many gardeners grow but can have trouble with in the North Carolina climate. The main issues tomatoes face in NC are Blossom End Rot and nutrient deficiencies. The former be cured with lime (or an antacid dissolved in water) and the latter with Epsom Salt. Both are less likely to happen if Tomatoes are paired with Marigolds, Carrots and/or Garlic. Some sources suggest planting Borage which has edible flowers and edible young leaves.
Tomatillo (Physalis philidelphica)
Tomatillos are the larger form of Ground Cherry but also are not nearly as sweet in flavor. Generally at the supermarket you will see the green fruit, but there are also purple fruited types. Tomatillos pair with the same things as Ground cherries but know that the plants get larger and may need more space.
Goji Berry (Lycium barbarum)
Goji Berry is a member of the Nightshade family that is rapidly gaining interest in the United States and for good reason. Goji Berries are full of antioxidants, vitamin A and C as well as fiver and iron. It’s noted that low growing plants like Ajuga, Sweet Woodruff or Creeping Jenny will happily grow near this plant and suppress weeds. In a container it is noted that annuals like Nasturtium and Sweet Alyssum are good companions. What you should not plant near a Goji Berry, is any other member of the Nightshade family or anything from the cabbage family. Goji Berries need space to do their best and the plants around them should not be competitive for nutrients.
Tobacco (Nicotiana tabacum) (Nicotiana rustica)
True smoking Tobacco can get very large, as individual plants can grow up to six feet tall. If you decide to grow this know that it will need space, and that it will be targeted by every hornworm within a few miles. If you’re not dead set on growing a crop of leaves for smoking tobacco can make for a excellent trap crop for things that otherwise would pillage your other Nightshades.
Tobacco, Flowering (Nicotiana alata) (Nicotiana syvestris)
Flowering Tobacco is the form of Tobacco that is not used for smoking, its main feature is its beautiful flowers which bring in pollinators. Flowering Tobacco does have a secondary use as a trap crop for Tobacco Horn Worms as they will often go after it before they attack Tomatoes. In terms of companion planting, Flowering Tobacco pairs well with Marigolds, Basil and Borage. You should never plant Flowering Tobacco near other nightshades as it shares pests and diseases with them and this can amplify your problems.
So, this completes the 2026 discussion about companion planting. I hope all of you out there found it interesting and if you have any questions please post them in reply to this post.
